bertrand-caron/fragment_capping: Beta Release: Fragment Capping

Beta release of the fragment capping project. The tautomer enumeration is now working, and switches for the most common problems (non-physical tautomers) have been provided: allenes and triple bonds in small rings (size <=7), hydrogenation of phenyl rings. Many test cases have been included (including warfarin, tetraphenylporphyrin).