• *Backwards incompatible: pymatgen.SETTINGS have been moved to
  pymatgen.settings.SETTINGS. In general, this should not lead to many breakages
  since most of these settings are used within pymatgen itself.
• *Backwards incompatible: pymatgen.loadfn and get_structure_from_mp have been
  removed since no one was using them.
• critic2_caller has been refactored. (@samblau)
• Improved hash for Compositon (@CompRhys)
• Fixes Outcar parsing for VASP 6.2.0. (@MichaelWolloch)
• Allow None for Gaussian functional, bset, charge and multiplicity (@eimrek)