Few more updates on gcm matrixes and basic tests for gcm matrixes
Remove MatrixInverter as a separate class since generic GCM matrix can do the same OOTB
Single implementation for solving third order polynomial equations
Update unit tests for matrixes a bit
Corrected materials for crack.xml. Task for fibers (fiber delamination and matrix cracking).
Merge remote-tracking branch 'origin/master'

Conflicts:
	src/libgcm/node/CalcNode.cpp
	src/tests/unit/anisotropic_matrixes.cpp
	src/tests/unit/math.cpp
Merge remote-tracking branch 'amisto/master'
Fix misprint in materials/testMaterials.xml
Cleanup after merge
FailureModel introduction
Fix principal stress calculation for pure hydrostatic stress tensor
Basic stress corrector for scalar destruction - just drop deviator
Basic infrastructure for continuum material failure models
	modified:   tasks/tests/crack.xml
Merge remote-tracking branch 'upstream/master'

Conflicts:
	src/libgcm/util/ThirdDegreePolynomial.cpp
	tasks/tests/crack.xml