Fixes for r41154 and r41155:

Fixes for r41154 and r41155:
* Boolean parameters are widely accepted to reduce readability. Replaced the new boolean parameters with class constant parameters instead.
* Re-added Revision::revText(), for backwards compatibility
* The getUser()/getUserText() changes near line 1223 of SpecialUndelete.php were incorrect, $file is an ArchivedFile not a Revision, and doesn't have any $isPublic parameters.