Merge pull request #46 from mlund/master

merge w master
Cleanup, geometry
Documentation; initial git version detection in cmake
Added SASA energy class incl. implementation into
playground/heyda/polymers.cpp
Added manybody class for angles, dihedrals; NDEBUG removed from compiler
w. RelWithDebInfo in Cmake; Fixed stockmayer test target hang due;
updated docs
Merge pull request #50 from mlund/develop

pull in develop