Initial Notification Updates and Support (#401)

* Bare bones of notifications working.

* Add MovieDownload event handler

To allow Download notificaitons

* Update pushover text to indicate movie

* Initial Notification Support

On Download and On Grab notifications should work.

* Telegram Notification Text

* Update Custom Script For Movies

* Update PP script WiKi page

Also added wiki page to Radarr wiki.

src/NzbDrone.Core/Notifications/Slack/Slack.cs

@@ -69,6 +69,10 @@ namespace NzbDrone.Core.Notifications.Slack
             NotifySlack(payload);
         }
 
+        public override void OnMovieRename(Movie movie)
+        {
+        }
+		
         public override void OnRename(Series series)
         {
             var payload = new SlackPayload