Fix a leak of PropagationMgrData
+ Do not use volumes for preview of Extrusion
+ Fix a regression: empty groups are not removed with contents
+ avoid too long waiting at creation of hypotheses due to use of
GEOMUtils::PreciseBoundingBox() in SMESH_Mesh::GetShapeDiagonalSize()
Rename the algorithms in the dialog box:
- Use existing faces => Use faces to be created manually
- Use existing 2D elements => Import 1D-2D elements from another mesh
- Use existing edges => Use edges to be created manually
- Use existing 1D elements => Import 1D elements from another mesh
