Port vtkTextActor3D to use vtkTextRenderer.

Change-Id: Ie86aa115529ad001564404b4b4efa796e80b899c
Add unicode support to vtkTextRenderer.

MathText doesn't currently support UTF16 and will convert to UTF8
before rendering, but this change will allow vtkTextRenderer to be
used with the Context2D framework.

Change-Id: If798bc40d14e8136f38d6f5d19919c4328e547b4
Add a vtkTextRendererStringToImage implementation.

This is used by the Context2D framework.

Change-Id: I10cd3575e268564a5c3bb16d79cfa89a08eed3fe
Fix MathText detection regexp.

The TextRenderer class was not identifying MathText strings that
start with "$" properly. This fixes the issue and tests the fix.

Change-Id: I35f08b4ec254429a88bd0b805a1ce8c33195d4e6
Merge topic 'forward-to-vtk-master' into pv-master

45985cf Merge topic 'fix-matplotlib-math-text-segfault' into master
73723f8 Merge topic 'AddSupportForBufferImageReaders' into master
169c9bf Fix segfault in vtkMatplotlibMathTextUtilities destructor
49360b7 Merge topic 'send-material-parameters' into master
1013348 Merge topic 'wrapping-external' into master
a55006c Check if the PythonD target exists
d8df7db Merge remote-tracking branch 'pvvtk/pv-master' into HEAD
5125955 Merge topic 'TreeHeatMap_RemoveInput' into master
6d8e160 Merge topic 'cleanup_RAdapter' into master
2b59d8a Merge topic 'execute-with-info-doc' into master
8087e82 Add vtkPainterDeviceAdapter::SendMaterialProperties()
2319cdc Merge topic 'fix_filter_precisions' into master
8803e22 Fix testing macros.
f830ef4 Fixing loss of point-precision in certain filters.
24b6f09 Merge topic 'vtkPolyData_documentation' into master
f2846ae Merge topic 'fix-warnings' into master
...
Merge remote-tracking branch 'pvvtk/pv-master' into HEAD

* pvvtk/pv-master:

Change-Id: Ie6c16b583147a8b836ae0db48a7365b9b5adc3f0
Disable python signal handlers in matplotlib module.

Change-Id: I891ef3ffa16aef481feb32949c78b2a9b113e9b2
Merge remote-tracking branch 'origin/master' into HEAD

Conflicts:
	Rendering/Matplotlib/vtkMatplotlibMathTextUtilities.cxx

Change-Id: I8c30e9852c1d819c1bb2fd0d75b6517742305cb7
Merge topic 'TextActor3D_TextRenderer' into master

aa8c363e Port vtkTextActor3D to use vtkTextRenderer.
Merge topic '13788-FixSignalHandlers' into master

4db96685 Merge remote-tracking branch 'origin/master' into HEAD
7ca26385 Disable python signal handlers in matplotlib module.
Merge topic 'Context2D_TextRenderer' into master

21b3d7aa Add a vtkTextRendererStringToImage implementation.
3b807281 Add unicode support to vtkTextRenderer.
Merge topic 'TextRenderer-fixRegExp' into master

98a40d34 Fix MathText detection regexp.
Simplify TextRenderer API, cleanup style.

Change-Id: Ia1c3474232e27324dbaaaa4f6f731b6444f43fa4
Add vtkProperty::RenderMaterial() method

This adds a new virtual method to vtkProperty named RenderMaterial()
which sends the given material properties to the graphics card.

Change-Id: I83e8b802e5096a7fc5a6b6d365e742b4433dd5eb
Merge topic 'SimplifyTextRendererAPI' into master

d3617b58 Simplify TextRenderer API, cleanup style.
Merge topic 'property-render-material' into master

b5ca589e Add vtkProperty::RenderMaterial() method