Update inbox after sending a message

Also change the event name to reflect how its being used, and stop
passing the message object around since it is not being used.

// FREEBIE

js/models/messages.js

@@ -228,7 +228,7 @@
 
                     conversation.save().then(function() {
                         message.save().then(function() {
-                            extension.trigger('message', message); // inbox fetch
+                            extension.trigger('updateInbox'); // inbox fetch
                             if (message.isIncoming()) {
                                 notifyConversation(message);
                             } else {