The possibility of filtering for index templates in the cluster state API
had been introduced before there was a dedicated index templates API. This
commit removes this support from the cluster state API, as it was not really
clean, requiring you to specify the metadata and the index templates.
Closes#4954
/_template shows: No handler found for uri [/_template] and method [GET]
It would make sense to list the templates as they are listed in the /_cluster/state call.
Closes#2532.
Alexander Reelsen
bleskes
Konrad Feldmeier
James Brook
Clinton Gormley
Lee Hinman
David Pilato