'ContentHandlerForModelID': Called when a ContentHandler is requested for
a given content model name, but no entry for that model exists in
$wgContentHandlers.
+Note: if your extension implements additional models via this hook, please
+use GetContentModels hook to make them known to core.
$modeName: the requested content model name
&$handler: set this to a ContentHandler object, if desired.
&$url: string value as output (out parameter, can modify)
$query: query options passed to Title::getCanonicalURL()
+'GetContentModels': Add content models to the list of available models.
+&$models: array containing current model list, as strings. Extensions should add to this list.
+
'GetDefaultSortkey': Override the default sortkey for a page.
$title: Title object that we need to get a sortkey for
&$sortkey: Sortkey to use.