Join [CohFrict]Mat, Phys and Ip2_.

Move them all into CohesiveFrictionalContactLaw.
Move Ip2_*_MindlinCapillaryPhys into HertzMindlin
Move Ip2_*_CapillaryPhys. into CapillaryPhys.
Move Ip2_FrictMat_* into FrictPhys
Move all NormalInelastic files into NormalInelasticPM
Join all InelastCohFrict files into InelastCohFrictPM.
Join all KinemC*Engine.* into KinemC__Engine.*
Set C++11 only for CXX-files, not C
Update LICENSE file, does not need exception any more
Cut off some header inclusions.