Reverting SpecialRevisiondelete.php back to r17880, to fix bug 9336 ( "Special:Revisi...

Reverting SpecialRevisiondelete.php back to r17880, to fix bug 9336 ( "Special:Revisiondelete broken in SVN head" )
The problem is that includes/SpecialRevisiondelete.php was in an inconsistent state - it was updated in r20446
(merge of rev_deleted branch), and then partially reverted in r20525 (i.e. there was some unintentional cruft left
over, including the change in the constructor params), and as a result stuff like
http://Hostname-Of-Wiki/wiki/index.php?title=Special:Revisiondelete&target=Main_Page&oldid=X would die with fatal
errors. (The diff between the before and after is shown here:
http://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/includes/SpecialRevisiondelete.php?r1=17880&r2=20525 ,
or from the command line, try: svn diff --revision 17880:20525 includes/SpecialRevisiondelete.php | less     )

I'm unsure whether I should be updating RELEASE-NOTES, but I'm leaning towards 'no', on the basis that no end-user
encountered this (cluster is on r20145), and that (hopefully) there should be are no user-visible changes as
a result of this revert.