Rename events to be consistent

- Make State.save() always throttle calls -- since that's the common
case.

- Immediate saves are now the exception, with State.saveImmediate().

- The function is called State.save(), so the dispatch event should be
'stateSave'.

src/renderer/controllers/torrent-list-controller.js

@@ -158,7 +158,7 @@ module.exports = class TorrentListController {
 
       // remove torrent from saved list
       this.state.saved.torrents.splice(index, 1)
-      dispatch('saveStateThrottled')
+      dispatch('stateSave')
     }
 
     // prevent user from going forward to a deleted torrent