- Merge all patches from @andreiled
- Add withoutSPH option to allow standalone build without SPH-specific code
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)
Update README, include descriptions for cmake options
Fix integration issues found after quick tests:
- More destruction-specific bits moved under withMeshRebuild define
- Max allowed time step calc updated to pass cas-test successfully
Add log4cxx configs into tests folders