0029346: Visualization, TKOpenGl - collect frame statistics

0029346: Visualization, TKOpenGl - collect frame statistics

Graphic3d_RenderingParams::ToShowStats - new option displaying rendering statistics.

OpenGl_FrameStats - new class for accumulating frame statistics.
OpenGl_Context::FrameStats() provides an access to the frame stats
used for currently rendered context.
OpenGl_View::Redraw() and OpenGl_View::RedrawImmediate()
resets counters within OpenGl_Context::FrameStats().

OpenGl_Layer::UpdateCulling() - simplified resetting of culling state for cullable structures.