The current dependency relationship in vtk is unclear and misleading.
This MR tries to rewrite them based on header files inclusion of headers
and source files in each module. Corner cases are considered and
modules are sorted in alphabetical order to facilitate future reference.
See details in my gitlab python based script project. In future we can continue
using this script to clean the VTK Dependency easily from
time to time.

vtk(.*)\(const vtk\1&\);\s*//\s*Not implemented[\.]*
to
vtk\1(const vtk\1\&) VTK_DELETE_FUNCTION;

vtk(.*)\(const vtk\1 &\);\s*//\s*Not implemented[\.]*
to
vtk\1(const vtk\1 \&) VTK_DELETE_FUNCTION;

vtk(.*)\( const vtk\1 & \);\s*//\s*Not implemented[\.]*
to
vtk\1( const vtk\1 \& ) VTK_DELETE_FUNCTION;

vtk(.*)\( const vtk\1& \);\s*//\s*Not implemented[\.]*
to
vtk\1( const vtk\1\& ) VTK_DELETE_FUNCTION;

vtk(.*) \(const vtk\1&\);\s*//\s*Not implemented[\.]*
to
vtk\1 (const vtk\1\&) VTK_DELETE_FUNCTION;

(operator\s*=.*);\s*//\s*Not\s*implemented[\.]*
to
\1 VTK_DELETE_FUNCTION;

After that, this finds basically nothing:

operator.*implemented

then manually reverted changed files in VPIC and KWSys folders.

SafeDownCast performs a series of virtual calls and string comparisons,
which is quite slow, especially when used in worker functions.

vtkArrayDownCast will switch between SafeDownCast and the more
efficient FastDownCast (only available for common vtkAbstractArray
subclasses) depending on whether or not FastDownCast is defined for
the specific array type.

vtkPLYWriter already handled RGB arrays. Making it also support RGBA
color arrays. In this case, the "alpha" component is simply ignored.

Code extracted from:

    https://gitlab.kitware.com/third-party/proj.git

at commit 41bdf05361007f8c5186f3df9944d86bb273ed13 (for/vtk).

Find/replace of:

with C++ counterparts.  Changed only vtk*.cxx files.
Didn’t touch .h or .c or any 3rd party.

This tool warns where macros should be using parens.
Fixed many issues it pointed out by either:
 - adding parens (which it can do automatically)
 - removed unused (or rarely used) macros
 - replacing macros with functions, notably vtkMath stuff

Some files use the names "texture_u" and "texture_v" instead of "u" and "v"

Also removed some dead code as a consequence,
like setting the deallocated pointer to null
then to a new address.

Also removed setting some ivars to null in dtors.

Mostly dead code, unused variables, or type
conversion warnings.

Change-Id: I33e29859d09f33888ae8774aa5f1c58b3dd559f2

A vtkSmartPointer<vtkUnsignedCharArray> was being assigned a raw
vtkUnsignedCharArray pointer, resulting in a leak. Changed assignment
to take a smart pointer instead.

Took the opportunity to make some raw pointers smart pointers instead,
making the implementation more consistent.

Also removed some debugging output that was left in.

Change-Id: I03693d0545f1c34969a868a48e5821671c10aebc

Used the following command:

find . \( -iname *.h -and -type f \) -exec perl -pi -w -e 's/__vtk(.*)_h/vtk$1_h/g;' {} \;

Fixes many, but not all, clang -Wreserved-id-macro warnings.

Change-Id: I694ff053cb204c70e37b261296f496064d91fc07

Fixed some minor leaks in error branches.
Prevent a malloc(0) from occurring by bailing beforehand.

Change-Id: I85cdc7d12a2598d477f3b956b86d445273698ed6

Change-Id: Ie2cf9e3d5848a22120899a3f867b45808f0f2e78

Change-Id: Ia1854719079236ec55eb1f7d0041798d09b4fac1

Did this for cxx files where another vtk include was already
using the "" style.  I find this is more correct, especially
for implementation files.

Change-Id: I632178a9af13991ccba96bfaabf5ccc4bfea3c18

The main kits are:

    vtkCommon
    vtkFilters
    vtkIO
    vtkImaging
    vtkInteraction
    vtkOpenGL (required due to a dependency cycle from
               vtkRenderingOpenGL on vtkImagingHybrid)
    vtkParallel
    vtkRendering
    vtkViews
    vtkWrapping

Modules which deal with a specialization of another module belong to the
kit related to the specialization (i.e., FiltersParallel and
IOParallelXML both belong to the vtkParallel kit) to avoid circular
dependencies that arise when put into the same kit as the "lesser"
module.

Change-Id: Icae0baa78d62cc0dcce84546541df600d4f311dd

These tests should work with either backend, and were inadvertently
merged with a hard dependency on OpenGL2 backend.

Change-Id: I25356b499d2317143db37e3fa59b04c5b1c53710

Change-Id: I6546ff164baca86afb1a73b896dd10b1bce2c005

Change-Id: I5f19b101063e1a25d4f5db5c4356ce5efffbd90d

Change-Id: I10a54acbd076e055d8071414f2fff1ebafe1653d

Also made some const correctness improvements,
which cascaded to clients of this class.

Other misc cleanup too.

Change-Id: Ic7688a12949a9b8cc752afb957e13317e50ba085

Fixes -Wmissing-prototypes warnings.

Change-Id: I577917ab639f522849731dd5023b2b3f6557387a

In other words, changed from the C to the C++ header name.
Did this only in .cxx files, and not in ThirdParty.

Change-Id: I81e2b2c7f2db00e98b37d507232fbc84022e8d8f

Change-Id: I94935b6fe4d5e76e453507f9387b5ca357286cab

Change-Id: I3e519825e71c5f4400ad869bda624a7399989d11

Add to the Testing/Data directory ExternalData content links mirroring
the content and layout we use from the VTKData/Data directory.

Add a CMake/vtkLegacyData.cmake module, included from CMakeLists.txt and
Testing/External/CMakeLists.txt, to call ExternalData_Expand_Arguments
for all data directories added from VTKData/Data.  This will bulk-fetch
all test input data currently used by tests of any module, enabled or
not.  We can make the DATA{} references more granular later.

Add a VTK_TEST_DATA_DIR variable to refer to the directory we tell the
ExternalData module to populate the real data files.  Replace references
to VTK_DATA_ROOT in test command lines (after -D) with references to
VTK_TEST_DATA_DIR.  Drop the VTK_DATA_ROOT CMake option and stop using
the VTKData repository.

Remove the TESTING_DATA option from the vtk_add_test_cxx API and remove
the VTK_DATA_ROOT option from the vtk_add_test_mpi API since all test
input data are now handled through ExternalData and Testing/Data content
links.

Change-Id: Id02490b76ea2e161b9038188264a4830485039d8