beginning editing of spatial solvers theory. I've just changed the first two sections so far. What to make many small increments as I suspect I'll want some undos.
more changes; part way through and need to pull.
I think I've updates these in some useful way?
Merge branch 'transport-josh-dev' of github.com:howland/pyne into tmpdev

updating (I think?)
Merge branch 'transport-josh-dev' of github.com:howland/pyne into tmpdev
cleanup of intro
added a paragraph about the methods in general.
fixed two quick spacing/comment things.
some formatting fixes, made citation an internal reference.
cleanup through ahotn general; got the section linking stuff to work.
finished cleanup of the theory manual. It's not very good, but it's not terrible. I'm going to send it to Sebastian for input.
fixed a few typos
Merge branch 'tmpdev' of https://github.com/rachelslaybaugh/pyne into transport-josh-dev