Running update.php on MySQL < v5.1 may result in heavy processing.
* RSS and Atom feeds generated by MediaWiki no longer include a fallback
stylesheet. It was ignored by most browsers these days anyway.
+* SpecialSearchNoResults hook has been removed. SpecialSearchResults is now
+ called unconditionally.
==== Renamed classes ====
* CLDRPluralRuleConverter_Expression to CLDRPluralRuleConverterExpression