Initial version of deployment guide

Addresses #304 

What else do we want in here?
@zenhack @gsilvis 
Quoting gsilvis (2014-11-04 11:09:42)
> > +boot times and avoiding accidental overwriting of their installed OS. Custome
> rs
> > +can explicitly request PXE booting for the next boot by calling `<insert API
> 
>    The should be node_power_cycle

Actually no, this is referring to an api call that doesn't exist - the
document refers to a lot of functionality that doesn't and won't exist
by release time.