1049492 - Add docs for the yum_repo_metadata_file.

https://bugzilla.redhat.com/show_bug.cgi?id=1049492
Remove periods for consistency.
Merge branch '1049492' into 2.4-release
Merge branch '2.4-dev' into 2.5-testing
Merge branch '2.5-testing' into 2.5-dev