Add pickle test for structures. Remove singleton decorator for PT.
Fix pickling for periodictable.
Merge remote-tracking branch 'mpmaster/master'

Conflicts:
	pymatgen/core/tests/test_periodic_table.py
Merge remote-tracking branch 'mpmaster/master'
Revert "Fix pickling for periodictable."

This reverts commit a8df86f9ab23f4b8df297e5dc58ef86f5b61381a.
Merge remote-tracking branch 'mpmaster/master'
Fix Pickle Test.
Pull changes from stable_py3.
Increment monty req. Refactor to use monty.functools.lazy_property.
Merge remote-tracking branch 'mpmaster/master'
Adopt best pratices in opening files with "rt" / "wt" for text files in vaspio.
Add POSCAR writing test.
More fixes to file writing.
Make sure all Vasp input files are done in unicode.
Increment monty requirements.
More unicode fixes. and cleanup.
Make sure cifio uses unicode.
Unicode fix in xyzio.
More unicode conversions for cssr.
unicode fixes for qchemio.