Fix different misprints and deps after latest commits
Removed cassert header includes
Link against libstdc++ by default
Make current code clang compliant
Refactored elastic material class to provide a way of specifying elastic
rheology matrix implementation
Replaced c-style function definition with c++ one
Replaced cout usage with LOG_* in libgcm and unit tests
Merge remote-tracking branch 'upstream/master'

Conflicts:
	src/tests/unit/anisotropic_matrixes.cpp
Test corrections: testRotation & '|=' gcm_matrix opeartor