Addresses some of the issues that appeared when running tox -edocs

Change-Id: I31133744ee0ddefa72c6590cb381de317e65633e

Also move the release notes to the bottom of the ToC, no need for
it to be at the top, that's prime real estate.

Change-Id: Ib3094a390a7214b320d02f77229f368aa4432c4e

Changes to the 'service list' commands for Identity v2 and v3:
* Document support for --long
* Add Description to v3 output with --long
* v3 output is now (ID, Name, Type), with (Description, Enabled) added with --long
* Change v2 output to match v3 output, with the absense of Enabled.
* Update doc to match

Closes-Bug: #1411337
Change-Id: I999e3df22f61350cdeba63bbb7d01145c2ffeeaf

Rather than pointing the 'project usage list' entry point directly to
ListUsage, this makes a ListProjectUsage subclass to alias the desired
command and still allow for changing behaviour or issuing a deprecation
messages.  This implementation simply sets a new 'deprecated' attribute
in the command class that cliff will use to skip this command when
generating help output.

The actual skipping of the command in help output is dependant on
https://review.openstack.org/147349 merging in cliff, this review will
simply have no effect on help output until a version of cliff with
that update is present.

The deprecation message printed is somewhat generic until
https://review.openstack.org/147381 is merged in cliff.
Until that is merged, the deprecation message will not have the name
of the actual command given by the user in it, but rather the text
'this command'.

Closes-bug: #1406654
Change-Id: Ie08d4f88d71a660fca1862405351109cd0aa86b6

Copy the content from the main wiki page that is not covered
elsewhere in these docs to the index page.

Change-Id: I94b68b7a0117d08fc8aba961c6de728118ef794e

This is a basic port of the Human Interface Guide from the OpenStack
wiki to our docs.  Content changes for updating, etc, will follow
in a separate review.

Change-Id: Id031cd6a27e045b249e16d00e41be24c55fb3c29