IO exists!

Ready for review!

Basic framework for the IO subpackage. Still need to add docstrings.
I think this has never been a problem, it's one of those things that we
prevent each other from doing, rather than Sphinx erroring.

On (Aug-19-14|13:06), Jai Ram Rideout wrote:
> > @@ -0,0 +1,94 @@
> > +r"""
> > +File I/O (:mod:`skbio.io`)
> > +=========================================
> 
> Make this underline the same length as the text above it (Sphinx y u no catch this???)
> 
> ---
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