Updating various doc items with 0.6 features, releasing soon, and removing references to things new in 0.4, which
has been out long enough to no longer be new.

Undocument override hosts (gone in 0.4, use -i "host1,host2" if you must, but want to leave that undocumented
as it's not a best practice so much.

Move see also blocks to bottom of each page to include reading docs, remove 'fork me' to avoid text overlap,
simply menu nav so folks find the chapter link.

interesting docs pages, some misc editing here and there.

https://github.com/ryan-roemer/sphinx-bootstrap-theme

Fix some rst related formatting.