Added TKOpenGlTest and TKD3DHostTest Draw Harness plugins.
TKOpenGlTest is automatically loaded by ViewerTest::ViewerInit().
Commands vgldebug, vvbo, vcaps and vuserdraw have been moved to TKOpenGlTest.
New command vglshaders lists GLSL programs defined by OpenGl_GraphicDriver,
previously implemented by "vshaderprog -list".
Added new command vdriver for graphic driver selection.
Removed erroneous code from command vstereo.
Aspect_IS_HOLLOW now an alias to Aspect_IS_EMPTY and Aspect_IS_HIDDENLINE does not implicitly enables mesh edges,
so that Graphic3d_AspectFillArea3d::SetDrawEdges() should be set independently.
OpenGl_ShaderManager now provides built-in GLSL programs for drawing mesh edges
in single pass (and on OpenGL ES which does not provide glPolygonMode()).
Graphic3d_RenderingParams::ToEnableAlphaToCoverage is now enabled by default
and properly handled at TKOpenGl level - enables coverage for Graphic3d_AlphaMode_Mask primitives.
OpenGl_PrimitiveArray now uses GLSL programs instead of glPolygonMode() by default,
which can be managed by OpenGl_Caps::usePolygonMode flag (desktop OpenGL only).
glPolygonMode() is also used as fallback regardless OpenGl_Caps::usePolygonMode flag
when GLSL programs are not supported (Geometry Shaders are required)
or stipple line style is required (not implemented within Face GLSL).
vaspects command has been extended by -setInterior -setDrawEdges -setEdgeColor -setEdgeType -setEdgeWidth
arguments replacing vsetinteriorstyle/vsetedgetype/vunsetedgetype commands.
vaspects now accepts arguments without "set" prefix.
ViewerTest::ParseColor() now parses RGBA color.
Redundant command BUC60738 has been removed.
AIS_ColorScale - fixed usage of uninitialized FillArea aspects.
