This commit was motivated by a fix for BUG #17739. This includes the
following improvements:

1. added properties on SpreadSheetView to control aspects like hidden
   columns. There were two mechanisms at play to control the columns
   that are hidden one in the Qt part and another in the View for
   exporting. Combined those to use a single approach.
2. Simplified pqSpreadSheetViewDecorator to update properties on the
   view for things like cell connectivity, field association etc. This
   make undo/redo, state save/restore work better for several of the
   parameters. A few still remain (see #18388).
3. Changed CSV export to use column labels. Also made CSV export always
   only export visible columns. The toggle we previosly exposed doesn't
   make sense. Export capability is meant to export what is shown in the
   view. The option to export extra columns was unnecessary.
4. Added a mechansim to vtkSMViewProxy subclasses to update their
   properties when representation are hidden/shown via the controller.
   vtkSMSpreadSheetViewProxy uses this mechanism to pick a good field
   association for the visible source.
5. pqExportReaction was messing up undo/redo stack. Fixed that.
   pqExportReaction should not be affecting the undo/redo stack at all.

(cherry picked from commit 4679f456)

This reverts commit 4679f456.

This commit was motivated by a fix for BUG #17739. This includes the
following improvements:

1. added properties on SpreadSheetView to control aspects like hidden
   columns. There were two mechanisms at play to control the columns
   that are hidden one in the Qt part and another in the View for
   exporting. Combined those to use a single approach.
2. Simplified pqSpreadSheetViewDecorator to update properties on the
   view for things like cell connectivity, field association etc. This
   make undo/redo, state save/restore work better for several of the
   parameters. A few still remain (see #18388).
3. Changed CSV export to use column labels. Also made CSV export always
   only export visible columns. The toggle we previosly exposed doesn't
   make sense. Export capability is meant to export what is shown in the
   view. The option to export extra columns was unnecessary.
4. Added a mechansim to vtkSMViewProxy subclasses to update their
   properties when representation are hidden/shown via the controller.
   vtkSMSpreadSheetViewProxy uses this mechanism to pick a good field
   association for the visible source.
5. pqExportReaction was messing up undo/redo stack. Fixed that.
   pqExportReaction should not be affecting the undo/redo stack at all.

Some are user-facing and some aren't user-facing. Found via `codespell -q 3 -D ~/Documents/diff-experiment/dictionary.txt --skip="./ThirdParty,./Qt" -I ../paraview-whitelist.txt`
whitelist contents were
```
ans
behaviour
cas
dum
initialise
initialisation
lod
nd
ot
pres
wont
```

This run of `clang-tidy` removes unnecessary `virtual` keywords and adds
`override` where necessary.

Improved code in vtkSMSaveScreenshotProxy that determines the scale
factors to use to achieve a target resolution when saving images. The
new logic allows for independent magnification factors which is crucial
to provide accurate target resolution.

This caused API on vtkSMViewProxy (and subclasses) to change, since now
`CaptureWindow` call takes in a 2-component magnification factor instead
of a single value.

Addresses #17567.

Cleaning up image capture code in vtkSMViewProxy and subclasses. Now, a
we provide a capable default implementation in vtkSMViewProxy itself.
Thus, removes duplicate(ish) code for several subclasses.

Next, we use an internal subclass of vtkWindowToImageFilter to call
`vtkSMViewProxy::StillRender` when the filter wants to request a render
for saving images. That overcomes the dependence on the interactor, thus
overcoming deadlocks when the interactor was missing (issue #17205).

Fix many warnings about overriden member functions not being marked
'override'.

This commit was generated automatically by running:

Utilities/Scripts/clang-format.bash --tracked

This was done automatically by running the script that was used already to
convert the documentation to doxygen style during the documentation
generation.

Commands:
/usr/bin/perl  $PWD/VTK/Utilities/Doxygen/doc_header2doxygen.pl  --to /tmp/tmpheaders --relativeto  $PWD/.  $PWD/Catalyst/Editions/Base/CoProcessing/Catalyst $PWD/Catalyst/Editions/Essentials/ParaViewCore/VTKExtensions/Default $PWD/Catalyst/Editions/Essentials/VTK/Filters/Extraction $PWD/Catalyst/Editions/Essentials/VTK/Filters/General $PWD/Catalyst/Editions/Extras/ParaViewCore/VTKExtensions/Rendering $PWD/Catalyst/Editions/Extras/VTK/Filters/Sources $PWD/Catalyst/Editions/Extras/VTK/IO/Legacy $PWD/Catalyst/Editions/Extras/VTK/IO/Parallel $PWD/Catalyst/Editions/Extras/VTK/IO/XML $PWD/Catalyst/Editions/Rendering-Base/ParaViewCore/ClientServerCore/Rendering $PWD/Catalyst/Editions/Rendering-Base/ParaViewCore/ServerManager/Default $PWD/Catalyst/Editions/Rendering-Base/VTK/Filters/Parallel $PWD/Catalyst/Editions/Rendering-Base/VTK/IO/Image $PWD/Catalyst/Editions/Rendering-Base/VTK/Interaction/Widgets $PWD/CoProcessing/Catalyst $PWD/CoProcessing/PythonCatalyst $PWD/CoProcessing/TestDriver $PWD/ParaViewCore/Animation $PWD/ParaViewCore/ClientServerCore/Core $PWD/ParaViewCore/ClientServerCore/Default $PWD/ParaViewCore/ClientServerCore/Rendering $PWD/ParaViewCore/ClientServerStream $PWD/ParaViewCore/Common $PWD/ParaViewCore/ServerImplementation/Core $PWD/ParaViewCore/ServerImplementation/Rendering $PWD/ParaViewCore/ServerManager/Core $PWD/ParaViewCore/ServerManager/Default $PWD/ParaViewCore/ServerManager/Rendering $PWD/ParaViewCore/ServerManager/SMApplication $PWD/ParaViewCore/VTKExtensions/CGNSReader $PWD/ParaViewCore/VTKExtensions/Core $PWD/ParaViewCore/VTKExtensions/CosmoTools $PWD/ParaViewCore/VTKExtensions/Default $PWD/ParaViewCore/VTKExtensions/Points $PWD/ParaViewCore/VTKExtensions/Rendering $PWD/Qt/ApplicationComponents $PWD/Qt/Components $PWD/Qt/Core $PWD/Qt/Deprecated $PWD/Qt/Python $PWD/Qt/Widgets $PWD/Web/Core $PWD/Web/Python $PWD/Web
\cp -rf /tmp/tmpheaders/* $PWD

Removed using the following command:

    perl -0777 -i -pe 's/(\n* *\/\/ *[BE]TX *\n+)+/\n\n/g'

on all vtk*.h, pq*.h and finished off by a few manual removals left over
from that.

These are reserved symbols.

Multi-view image capture was not handling transparent background
properly. Fixed that.

Previously, if Render() was called before Interact(), we couldn't
support that since the interactor cannot be created safely after the
window has been created. To address that issue, we now update simple.py
to create the interactor right after the view is created and before the
render is called. This will address most use cases.

Change-Id: Ic39f22959756ad6a7ef4e875ef11be25b15f6b0e

If a view has a hint "ShowOneRepresentationAtATime", then it implies
that the view can only show 1 data-representation at a time.
vtkSMParaViewPipelineControllerWithRendering::Show() ensures that the
such views hide other representations that may be currently visible.
This is a better approach to handling this in Qt subclasses since now it
works as expected from Python as well as the undo/redo stack doesn't get
confused.

Change-Id: I33fd32c2d1e517ad16ff06f1526b852e4f89f12e

The idea is basically to set the background color to black, take a
screenshot, then white and take another screenshot. From the difference
between the two images, we can determine whether the background is
showing through or not.

For translucency, the HSV value is calculated from each screenshot and
the alpha is the difference in the V component. The color values from
the black image are used since it doesn't change the input values at
all.

Change-Id: Icace035561660d6442688aeded622cac261d3886

Fixed check for drawable to work properly for context views as well (not
  just render views). Fixing logic added by commits c2360275 and
c8736fa3. vtkSMViewProxy should not have code that works with
vtkPVRenderView alone. This fixes LoadStateMultiView test issues on OsX.

Change-Id: I8ef899cb47fafae75fa57ef0a603c7a12e48e00e

Deprecating pqDisplayPolicy for the most part.
vtkSMParaViewPipelineControllerWithRendering is now the class that
manages all the logic in pqDisplayPolicy instead.

Updating vtkSMViewProxy API to add CanDisplayData() which is needed for
vtkSMParaViewPipelineControllerWithRendering to work correctly.

Fixed usage of pqDisplayPolicy is core ParaView. Plugins and examples
still need to be updated.

Change-Id: I4188acaceedde2e0fe8e927e142b9a62615515f9

Created a new behavior class, pqApplyBehavior, that encapsulates the
logic that must ensure after an apply. Moving relevant parts out of
pqPropertiesPanel to this new class.

pqApplyBehavior now also handles resetting or growing on transfer
function range on each apply.

Added mechanism to
vtkSMTransferFunctionProxy/vtkSMTransferFunctionManager to reset the
transfer function range using the ranges from all available
representations.

Added a new option in vtkPVGeneralSettings to allow user to pick
between growing transfer function range and clamping transfer function
range on each Apply.

Change-Id: I2e75953437785dfdd15a10bafc521d7a26298c11

Change-Id: I9eb710f6a584a0c67a357f9af3908a7e334b4da4

Fixing export macros (and other header testingn failures).

Change-Id: Ib92aed44cd105f66abad99b88edccddb34ae9859

This fixes the issue reproducible as follows:
With remote render enabled create a sphere and hit apply. Now change the remote
render threshold (from Python or GUI) to a large value (forcing local render).
One would not see anything rendered, since the client was under the impression
that the geometry had already been delivered. Fixed that by keeping separate
timestamps on the client side to determine when geometry has been deliveryed in
what rendering mode.

Adding a new key, VIEW(), to the ProcessViewRequest() call to make it easier for
representations to access the view that is calling the passes.

* Restructuring render in vtkPVRenderView to never to data parallel
  communication unless doing parallel rendering.
* started laying ground work for how I want the delivery components to play
  together. API is still under development.

This is first step towards supporting tabs in a tile-display configuration.

Change-Id: I5f8b8523901e2f837bae5dedf7552ed1fd74283f

Fix conflicts with collaboration branch.

* Created new ParaViewCore directory in place of Servers.
* Moved classes from old directories to new ones.
* Removed some obsolete classes that were lingering in Filters/ServerManager.

Added new vtkPVSession that provides API for ParaView sessions that can be
accessed from the the classes in Servers/Filters.

This commit refactors ParaView's existing views and representations which are
heavily ServerManager to move most of the complicated logic to VTK-level
representations and views.

This commit includes changes to convert all proxy level views/representations to
VTK based views/representations as well supporting infrastructure for parallel
rendering/delivery mechanism required by the VTK views in ParaView.

Details about this design can be found at:
http://paraview.org/ParaView3/index.php/Views_And_Representations

The CVS $Revision$ keyword replacement will no longer maintain these
macros automatically.  They were used only to implement CollectRevisions
and vtkObjectBase::PrintRevisions, an API that was never used.

Automated as follows:

  pass 0:
  catch templates
  ---------------
  $ git grep 'vtk\(Cxx\|Type\)RevisionMacro' | grep '<'

  pass 1:
  main changes
  ---------------
  $ git grep -l '^vtkCxxRevisionMacro' | while read file; do
    echo "$file" 1>&2
    perl -i -ne 'print unless (/^vtkCxxRevisionMacro/ and /\)/)' $file
  done
  $ git grep -l -e 'vtkTypeRevisionMacro(' | while read file; do
    echo "$file" 1>&2
    perl -i -pe 's/vtkTypeRevisionMacro/vtkTypeMacro/g' $file
  done

  pass 2:
  verify
  ---------------
  $ git grep 'vtk\(Cxx\|Type\)RevisionMacro'

Fixed multi-line vtkCxxRevisionMacro and templates by hand.