More cleanup.
Plenty of simplification and cleanup for pointgroup code.
More streamlining and use of python idioms.
Improve docs.
Minor spelling error.
 More doc updates.
Add support for mson/json to smartio.
Add read_mol, write_mol to smartio.
Remove vasprunxml from mol options.
Many unittests for smartio. Add write_file method to GaussianInput.
Update doc.
Massive update to usage docs, with new tutorial to Molecule functionality.
Update docs.
Add a D5d molecule for symmetry testing.
Speed up point group code.
fixed bug in timestep sampling for diffusion_analyzer. Now actually limits number of dt
samples to 200.
Merge branch 'master' of github.com:materialsproject/pymatgen
modify Vasprun to store the ionic_step_skip parameter
Add step-skip consistency check
Reverse previous change.