+ minor changes in docs
+ fix other problems with Mesh Dialog:
1) at mesh edition, old hypothesis remain assigned after playing with
Mesh Type and Hypo Sets (change is in isSelectedHyp())
2) When a 3D algo is unset due to change of Mesh Type, its hypotheses remain
assigned and a new hyp can be created
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()
+ Optimize SMDS_VolumeTool::IsFreeFace()
+ Add icons for Evaluate and Change Sub-mesh order
+ Make "Meduim nodes on geometry" ON by default
+ Disable "Group on geometry" if mesh is not on geometry
+ SMESHGUI_MeshOp: fix switch from Sub-mesh creation to Sub-mesh edition
