context-based variables.
&$lessVars: array of variables already added
+'ResourceLoaderJqueryMsgModuleMagicWords': Called in
+ResourceLoaderJqueryMsgModule to allow adding magic words for jQueryMsg.
+The value should be a string, and they can depend only on the
+ResourceLoaderContext.
+$context: ResourceLoaderContext
+&$magicWords: Associative array mapping all-caps magic word to a string value
+
'ResourceLoaderRegisterModules': Right before modules information is required,
such as when responding to a resource
loader request or generating HTML output.