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.
Extended SelectBasics_PickResult structure by myObjPickedPnt field, which contained the value of the 3d point on the selected object.
Changed all Overlaps methods. Parameter theDepth replaced on object of the structure SelectBasics_PickResult. This approach will be able to add new fields to SelectBasics_PickResult structure without big changes in modules which contained Overlaps method.
