Remove remnants of exporting Rhino files from GUI.
Remove inactive remnants of importing XSec as surface.
Better handle capping failure cases in VspSurf.

Make sure UWSkip is always updated before returning from CapUMin/Max.

Don't assert on failure cases -- they aren't hard failures (chord==0).
Track Cap success/failure and check when setting tessellation parameters.
Change total chord variable name to not be confused with tip chord.
Add m_UpdateBlock to prevent recursion of Geom::Update.