[MERGE] Add helper class versionedfile.VersionedFilesDecorator for use with RemoteRepository in future.

[Bundle Buggy]

Bundle Buggy has detected this merge request.

For details, see: 
http://bundlebuggy.aaronbentley.com/project/bzr/request/%3C1235473287.30336.3.camel%40lifeless-64%3E
Project: Bazaar