Clean up both the releasenotes 'conf.py' and some remaining pieces of
the main 'conf.py'. In the case of the former, it looks like this was
copied from Cinder's config, and retains a lot of unnecessary config for
same. Remove it all.
It is also necessary to remove a docstring from 'os_brick/__init__.py',
as this was causing build issues. No idea how this was building
previously.
Change-Id: I2ca913c2ebcf2030642b18c72af180bb8f03b288
f3eb28dcf6