1) Zoom persistence mode now fixes object in pixel coordinates and is independent on view size
2) Used gp_GTrsf instead of gp_Trsf SelectMgr_ViewerSelector to store Graphic3d_Mat4d
3) Zoom persisted objects changed behavior (become bigger) therefore test cases were updated according to new state.
4) Corrected scale for rectangular frustum
Updated test for manipulator
Add one more pre-defined Z-layer Graphic3d_ZLayerId_BotOSD.
Define new Transformation Persistence flags Graphic3d_TMF_2d and Graphic3d_TMF_2d_IsTopDown
for displaying objects in screen coordinates.
Anchor point defines angle of the screen to display the object in similar way as for Graphic3d_TMF_TriedronPers.
Extend Draw Harness command vdisplay with new options:
-overlay as alias for -toposd.
-underlay and -botosd.
-noselect to prevent automatic selection activation.
-dispMode and -highMode to define displaying and highlighting modes.
-2d, -2dtopdown and -3d to manage displaying in screen coordinates.
-trsfPers and -trsfPersPos for Transformation Persistence options.
Drop command vsettransmode, replaced by vdisplay.
Correction of test-case bugs vis bug641
