remove runtime dep on python-pbr
sync parameter values with keystone-dist.conf
Use updated parallel install versions of epel package

Use SQLAlchemy >= 0.7.8 WebOb >= 1.2 Routes >= 1.12.3 PasteDeploy >= 1.5.0
and depend on the parallel installable
versions of these packages to satisfy those requirements.
sphinx10 in el6 does not have apidoc extension

rpm build was failing with:
Running Sphinx v1.0.8
sh: git: command not found
Extension error:
Could not import extension ext.apidoc (exception: cannot import name apidoc)

Also revert to oslo.sphinx to be compatible with python-oslo-sphinx RPM
see https://bugzilla.redhat.com/show_bug.cgi?id=982428#c12