Merge topic '14023-plot3d-function-support' into pv-master

1a317ca Merge topic 'NewFeatureToTreeHeatmapItem' into master
9957514 Merge topic 'osmesa_extensions' into master
c6a02ee allow os mesa to provide more than version 1.1
d2e8d45 Merge topic 'ugridreader-test-fix' into master
5c052ec Merge topic 'multi-block-color-support-2' into master
bedc076 Merge topic 'osmesa_extensions' into master
f850202 Merge topic 'plot3d-function-support' into master
5a824a9 Several enhancements to the Plot3D readers.
d8229df Fix camera problem in TestXMLUnstructuredGridReader.
a5278cd Merge topic 'scalarbar-warnings' into master
13f52d0 Merge topic 'istyleimagepropertytest-fix' into master
5c1e16d Fix logical error in TestInteractorStyleImageProperty.
93c5d8b Merge topic 'documentation_updates' into master
b035ffd ENH: Expose the collapsed tree to the API.
a80bad6 Fix unused variable warning.
a142841 BUG: Fix GetProcAddress call when OSMesa is being used.
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Merge topic 'update_vtk_master' into pv-master

7d074c5 Merge topic 'clamp-interpolated-scalars' into master
b1b53ec Merge topic 'fix_piston_compwarns' into master
c166809 Merge topic 'Fix-HTG-signed-warning' into master
39b7a34 Fix signed/unsigned warning in HTG.
35114ed Merge topic 'HTG-FixTestWarning' into master
c903fe9 Fix warning on HTG 2D FullMaterial test.
5e8adb4 Merge topic 'Enh-HTG-Add-BSF-GlobalIndexingMode' into master
1b3c1b5 Merge topic 'polygon_select' into master
962324b Added polygon selection to hardware selector.
8c73f97 Clamp integer scalars in InterpolateTuple().
672b314 Merge topic 'plot-colors' into master
c6888ea Merge topic 'C++11-warnings' into master
1edea1c Removed C++11 extensions warned about by clang
e420ff3 Merge topic 'ImageReader-CastAlign' into master
57745b3 Fixed -Wcast-align warning by changing variable type.
be9b924 Merge topic 'plot3d-improvements' into master
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Merge remote-tracking branch 'pvvtk/pv-master' into HEAD

* pvvtk/pv-master:

Change-Id: I45c2d02fe43125f0dc22976de844190db6969f3d