When we fetch the list of affected files in a given changelist, perforce

reports deleted files with a revision number. That revision corresponds to the

deleted version of the file, and p4 print will just return empty. This is

similar to edits, where the revision is actually the post-edited revision

rather than the pre-edited version, and we need to decrement the revision.

Ran through some p4 deletes.
Ran unit tests.