* Introduced FileRepoStatus -- result class for file repo operations.

* Introduced FileRepoStatus -- result class for file repo operations.
* Ported file delete/restore to the filerepo framework. Some user-visible changes in error reporting.
* $wgSaveDeletedFiles has been removed, the feature is now enabled unconditionally. Added a "deleted" directory for the default location, protected by a .htaccess file and the practical obscurity of content hashes.
* Fixed bug 2735: "Preview" shown in title bar for action=submit on special pages
* Removed "restore" links from the deletion log embedded in Special:Undelete
* Added img_sha1/oi_sha1 fields, preserved through upload, delete and restore
* Referenced the new oi_metadata etc. fields to preserve metadata across upload and delete/restore.