Simplify code. Since the rational fraction of both x and 1 -x  (x E (0,1) ) will have the same denominator there is no reason to take the lowest common multiple of the two denominators
Fix vaspio_set to work with new antiferromagnetic transformations
Make determine min cell a class method.
Merge branch 'master' into mag

Conflicts:
	pymatgen/transformations/advanced_transformations.py