Updated openstack/openstack
Project: openstack/taskflow  dbf117aaf5eaf59a8b5d3c0516add2b708ce3e73

Documentation cleanups and tweaks

Apply some adjustments on the docs by rewording certain
statements, linking to the correct classes and methods and
linking to the correct exceptions to make it easier for
users to follow the docs and there associated types and links.

Change-Id: I03aac77c814fc4c376003f09a45559a0995b3c6c