Change StructureMatcher's internal representation of a structure to a large
masked table instead of multiple smaller ones to allow more complicated
Comparator objects (with non-transitive mapping)
Merge branch 'master' into structure_matcher

Conflicts:
	pymatgen/analysis/structure_matcher.py
added comparator for checking ordered to disordered fits
Merge branch 'structure_matcher' of github.com:materialsproject/pymatgen into structure_matcher
Merge branch 'master' into structure_matcher
Finetune phase diagram imports.