OpenGLPolyDataMapper2D for OpenGL was clipping the z components
between -1,0 or 0,1. The logic is a bit different in OpenGL2 versus
OpenGL. I believe it has somethiong to do with where the
transformations are performed. I'm pretty sure z-clipping should not
apply for 2D mappers. A new test was added that has polydata with a
large z range.

NOTE: To see the bug, download this patch and revert to the
original mapper:

git checkout master Rendering/OpenGL2

and
ctest -R TestLegendBoxActor2

aa891852 Fixed test timeout
269aa961 Accelerated and thread-capable attribute data processing
Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !1282

fad05318 make OSX use the generic superclass SupportsOpenGL
Acked-by: Kitware Robot <kwrobot@kitware.com>
Reviewed-by: Berk Geveci <berk.geveci@kitware.com>
Merge-request: !1280

fbff2fe7 fix for props that have no bounds with EDL
Acked-by: Kitware Robot <kwrobot@kitware.com>
Reviewed-by: Berk Geveci <berk.geveci@kitware.com>
Merge-request: !1275

try to reove special subclass version of SupportsOpenGL
as the superclass one should work.

ba00d36a Enable/disable clipping planes in vtkOpenGLGlyph3DMapper
Acked-by: Kitware Robot <kwrobot@kitware.com>
Reviewed-by: Ken Martin <ken.martin@kitware.com>
Merge-request: !963

5c1017a2 Fixing Intel compile error.
Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Ben Boeckel <ben.boeckel@kitware.com>
Reviewed-by: Dan Lipsa <dan.lipsa@kitware.com>
Merge-request: !1276

6f62b2d5 Move re-indentation utility to the Maintenance dir.
Acked-by: Kitware Robot <kwrobot@kitware.com>
Reviewed-by: David E DeMarle <dave.demarle@kitware.com>
Merge-request: !1278

582187de Fix the functional bag plot extraction filter.
Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Mathieu Westphal <mathieu.westphal@kitware.com>
Merge-request: !1110

This is a python script that changes the Whitesmiths indentation
style to the Allman indentation style that is currently more popular.
This script will only change the brace indentation, it will not change
the code in any other way, so "git blame" results will be mostly
unchanged after re-styling.

6c456e0f Merge branch 'release' into HEAD
Acked-by: Kitware Robot <kwrobot@kitware.com>
Reviewed-by: David E DeMarle <dave.demarle@kitware.com>
Merge-request: !1274

3ffe6bfb Improving finding libGLdispatch.so.0 for EGL
Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Dan Lipsa <dan.lipsa@kitware.com>
Reviewed-by: Utkarsh Ayachit <utkarsh.ayachit@kitware.com>
Merge-request: !1268

The EDL pass iterates over all props and uses their
bounds but some props return null. This topic checks
for that case and handles it.

38c3e3cd adding a missing mapper
b16a9f4f implement the always on top option for Contour
Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Yumin Yuan <yumin.yuan@kitware.com>
Merge-request: !1267

* release: (25 commits)
  Fixed volume rendering not working for cell data
  Fixed typo which resulted in test failure
  Added API to turn on/off jittering
  Fixed edge conditions with clipping
  ...

Primarily brings in volume rendering fixes.

f23ee19a Merge remote-tracking branch 'origin/master' into volume_fix_cell_data_release_updated_master
2140f97b Fixed volume rendering not working for cell data
b0444dc4 Fixed typo which resulted in test failure
0038dd88 Added API to turn on/off jittering
1f59f0e7 Fixed edge conditions with clipping
fc779f03 Turn off jittering
d9d1959e Fixed clipping for oblique view angles
8a0518a9 Fixed minor logic issue with when to terminate the trace
...
Acked-by: Kitware Robot <kwrobot@kitware.com>
Reviewed-by: David E DeMarle <dave.demarle@kitware.com>
Merge-request: !1269

79cafcfc tcl test as well
51f7345f better and tighter options for clipping range
Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !1258

aae92bb6 super small bug in opengl version query
Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !1270

was retuning the wrong version 5.5 was a giveaway that
something was wrong

Conflicts:
	Rendering/VolumeOpenGL2/vtkOpenGLGPUVolumeRayCastMapper.cxx

4f18cdc4 ScalarBar Missing Baseline
Acked-by: Kitware Robot <kwrobot@kitware.com>
Reviewed-by: Joachim Pouderoux <joachim.pouderoux@kitware.com>
Merge-request: !1265

forgot to update the tcl version

48588518 Work around test failure due to OpenGL2 not running on some machines
Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !1266

it could be that the lines mapper needs offsets as well

516ffdda try for more recent opengl versions first
Acked-by: Kitware Robot <kwrobot@kitware.com>
Reviewed-by: Berk Geveci <berk.geveci@kitware.com>
Merge-request: !1261

make the AlwaysOnTop option do something for the
OrientedContourWidgetReppresentation class

ec4014d4 Moving the SupportsOpenGL call to parent class to avoid code duplication.
16120cba Initializing the object when SupportsOpenGL() is called.
Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !1260

The old automatic clipping range code always grew
the bounds to be double the required bounds. With the
zbuffer being so heavily nonlinear this was not a good
for many situations. This topic alows you to control
the bounds expansion to it can be much tighter which
if you are calling ResetCameraClippiNgRange every time
the camera changes it should be set to 0.0 not the default
of 0.5.

e5425ed8 Regression test image
a13950ca New regression test images
7a31d165 Renamed filter for consistency
bf20a5aa Pass input attribute data to output
bdc02994 Cleaned up documentation
707da941 New class generates data from implicit function
Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !1259

4173dbea Proper pipeline behavior
045eac98 Test cleanup
956b5591 Refactored kernel API to support different basis
eadf3ec1 Created new Filters/Points module
ae3d4315 Preparation for reorganization
e5c4dd6d Added new class for oriented gaussian distributions
b92e2cbc Compiler warnings
0fb06f89 Compiler warnings
...
Acked-by: Kitware Robot <kwrobot@kitware.com>
Reviewed-by: Berk Geveci <berk.geveci@kitware.com>
Merge-request: !1062