This change removes the soon-to-be unused "warnerrors" setting,
which will be replaced by "warning-is-error" in sphinx
releases >= 1.5.[0] This also pre-emptively fixes most warnings
that came up when testing with sphinx >= 1.5:
- Multiple cases of Opts
- Redundant loading of todo extension
Added a comment to not to enable the new sphinx setting until
the issues with Changlog building are fixed.
Added setup.py to the list of files to ignore when building
docs.
[0] http://lists.openstack.org/pipermail/openstack-dev/2017-March/113085.html
Change-Id: Ia0079c6b551dd3896bc3d922a477f927757bd61b
7bf7619104