Use oslosphinx in keystonemiddlware for documentation

Start using oslosphinx to generate the themes and static content,
rather than hosting our own copies.

Change-Id: I014ef5f974835d52dbb4598c7d357ecafa1da8a2
Merge "Use oslosphinx in keystonemiddlware for documentation"
Updated from global requirements

Change-Id: Ie301346cda80246edf6516a83ff6618613011eaa