Treat warnings as errors when building documents to early spot problems.
Fix api-ref set up:
* Add openstackdocstheme for api-ref building instead of oslosphinx and
configure it properly.
* Setup api-ref log-a-bug correctly for this project.
* Remove unneeded extra install command
Fix install-guide set up:
* Add tox environment
Fix releasenotes set up:
* Fix conf.py settings to build without errors, remove index, we don't
need it.
fix docs set up:
* Use Sphinx 1.5 warning-is-error option for normal build_sphinx.
* use oslo sphinx
* Remove wrong static path setting
Change-Id: I07ce9db9fdb526ab4b083c65afa99c38bb508146
15233f9bf3