* Removed info(), purge(), revert() and rollback() from the Article class; they
have since become subclasses of the Action class. (deprecated since 1.19)
* SearchEngineReplacePrefixesComplete hook was removed.
+* The "jquery.json" module has been deprecated. Use the "json" module instead.
* Removed HTMLForm::addJS(). (deprecated since 1.18)
* Removed LogEventsList::showHeader(). (deprecated since 1.19)
+ * Removed ImageGalleryBase::useSkin(). (deprecated since 1.18)
==== Renamed classes ====
* CLDRPluralRuleConverter_Expression to CLDRPluralRuleConverterExpression