I think this is intentional. Simple just keeps a number of versions, and names them based on when the file was modified. Staggered tracks when the versions were created so it can keep x amount of them in a certain time interval etc.
1. Forces all versioners to use the same tagging, meaning that trash can versioner will start adding timestamps (cleanup is mtime based so it's ok)
2. Removes Rename function which seems not to be used anywhere important anymore, and TryRename is now RenameOrCopy
3. Versioning (and ton of other stuff) should now happen across filesystems when possible.
4. Adds versioning support for untagged and old file.txt~2014... tagged files. (There was no other way, in order to support trashcan versioner)