Merge 'cas-integration' branch manually - a lot of small fixes
Implement free sliding contact condition and make it default one
Contact treshold autodetect - initial draft
Conflicts solved:
	gcm/system/TetrMeshSet.cpp
Update ColDet to take relative nodes speed into account. It doesn't trigger contact flag now if distance doesn't shorten.
Add energy norm to make the scheme quasi-conservative
Add FixedBorderCalculator support into TaskPreparator
Basic continuum destruction model impl
Fix destruction - la and mu should be dropped only once
Basic destruction test
Experiments with mesh quality check and fix
Commit ugly mesh rebuild impl - just for historical purposes

Conflicts:

	gcm/meshtypes/TetrMesh_1stOrder.cpp
	gcm/system/TetrMeshSet.cpp
Add withMeshRebuild option to turn on highly experimental mesh rebuild manually (rebuild is off by default and it should be so)