[GCAD] Fixed OBB3d:IntersectLine ().
[GCAD] Added LineTraceIntersectionType and LineTraceResult.
[GCAD] Added TraceLine functions for ISpatialQueryables.
[GCAD] Frustum3d.FromScreenAABB () and NativeFrustum3d.FromScreenAABB () now initialize the near plane to 0.
[GCAD] Added SelectionType, Selection and SelectionRenderer.
[GCAD] Reorganized the context menu code.