modified __getattr__ of sites to work with the pickle module
updated __getattr__ of the Species class to work with the pickle module
added __getnewargs__ to Element to allow unpickling of cached_class
updated getattr in alchemy.materials to be compatible with pickle
Updated transmuters class to allow for multithreading of append_transformation
Change barycentric to use solve instead of inv.
Faster.
allow KeyError in addition to ValueError for atom_site_occupancy. Some CIF files omit this key which implies occupancy = 1
Fix rest test for new db update.