This change adds the parameter `master_timeout` to the rest requests that can write to a watch PUT, ACK and DELETE.
Also add support in the rest tests to verify that this is accepted.
Fixes: elastic/elasticsearch#416
Original commit: elastic/x-pack-elasticsearch@4cc1c50f2c
This change changes the watch specific actions put/get/delete/execute/ack to be watcher.<action>_watch.
Original commit: elastic/x-pack-elasticsearch@86a91cb141