Rbarlow rename parameter for consistency

This pull request includes the commit from #1095, so please either review that one first, or just review the one commit this adds[1]. Apologies for the confustion, but they are different enough to be verified separately.

[0] https://github.com/pulp/pulp/pull/1095
[1] https://github.com/pulp/pulp/commit/471389187e3d4a91b06b5483011b63dbe1c48685
consider using common.config.parse_bool() for consistency.