+* Removed getLang() from IContextSource and subclasses. (deprecated since 1.19)
+* Removed setLang() from subclasses of IContextSource. (deprecated since 1.19)
+* Removed WebRequest::escapeAppendQuery(). (deprecated since 1.20)
+* 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)