Moved a few docs/pointers to docs around.

* INSTALL.rst is now at top level. This is more typical, and consistent
  with having HACKING.rst at top level. Links have been changed to
  match.
* INSTALL.rst now refers directly to HACKING.rst; The extra level of
  indirection is weird, and the only real piece of additional info is a
  link to the stuff in moc-public. Users will probably have already
  looked at the readme anyhow.
* Corrected some capitalization in the deployment guide.