Change-Id: I4d6702d0b2a6c4fe224a8c59808a579b6c6916a0
&$model: the model name. Use with CONTENT_MODEL_XXX constants.
'ContentHandlerForModelID': Called when a ContentHandler is requested for a given
-cointent model name, but no entry for that model exists in $wgContentHandlers.
+content model name, but no entry for that model exists in $wgContentHandlers.
$modeName: the requested content model name
&$handler: set this to a ContentHandler object, if desired.