Added tangent stiffness support for linear/exponential cohesive crack models.
Merge branch 'master' of www.oofem.org:/data/git/oofem
XFEM: Implemented support for transition from branch functions to
sgn-enrichments when cracks propagate (no mapping of state variables yet
though). Also made various small fixes in the XFEM module.
Merge branch 'master' of https://github.com/Micket/oofem
XFEM: Fixed warning.
Merge branch 'master' of github.com:Micket/oofem

Conflicts:
	tests/sm/xFemCrackValBranch.in
Some cleanup in enrichmentItem wrt shell7base implementation

+ changes in fracturemanager
Merge branch 'master' of github.com:JimBrouzoulis/OOFEM_Jim