Revert "Revert "Bug fix for EnumlibCaller. Fixes #78.""

This reverts commit 80044c6791bb8a971d205df66e99649bed420a71.
bugfix to yesterday's pdmaker bugfix
Merge branch 'master' of github.com:materialsproject/pymatgen
More more robust enumlib. Fixes #78,
Minor efficiency improvement.
More efficient symmetry breaking check.
Minor doc improvement.
Yet more speed up.
cleanup.
add molecule matcher test case has no attribute GetAtomicNum
fix no attribute GetAtomicNum bug
reformat to comform PEP8
Merge remote-tracking branch 'origin/master'
skip molecule_mather unit test if OBAlign is not present
Merge branch 'master' of github.com:materialsproject/pymatgen into ff_dev