add test for #378
Fixes #378
Fixes #385
Fixes #392
- fixed a bug in UFF/TorsionConstraint.cpp and MMFF/TorsionConstraint.cpp
  which caused issues with negative angles
- made also UFF/AngleConstraint.cpp and MMFF/AngleConstraint.cpp more
  robust against angle ranges involving negative values
- added relevant C++ and Python tests

Conflicts:
	Code/ForceField/UFF/Params.h