Docs

Here are the beginnings of documentation. I've also got this building on readthedocs: dit.rtfd.org . it's got a number of sphinx extensions turned on at the moment.

read the docs is actually pretty neat... so because autodoc is enabled, we need to install dit to pull the method info, so rtd builds a virtualenv, installs the packages we need (iterutils, numpy, six), as well as installs numpydoc, then builds the docs. at the moment it apparently will build nightly (and will build for new version tags too!), but we can put a post-commit hook on github to trigger builds whenever we commit.