Pyeparse

Adds pyeparse. Review / merge after the whitespace PR is merged.
Ahh crap. I forgot to update pyeparse when I abandoned pytables for h5py recently. We should hold off on this PR until I fix that, since it will immediately remove the pytables install requirement...

I might be able to get to this in a few days, but I can definitely do it in early Jan. Can this PR wait until then?