[master 20170119 E3] 'colvars/distance.py' (Rev. 2) (see notes)
[master 20170119 E3] 'colvars/distance.py' (Rev. 2) (see notes)

- Implemented a new modular scheme
- Axes difference now taken care of
- Readability vastly improved!
- Not the most efficient implementation, but it should work!

KhunWasut/chempython