Remove usage of extension.trigger

This trigger function uses chrome's runtime message passing api, which
traverses between different windows in our runtime, but we only trigger
the updateInbox event from the backgroud page, so we don't need to use
that api, which requires some extra cpu/memory overhead.

// FREEBIE

js/background.js

@@ -137,13 +137,13 @@
                 var message = initIncomingMessage(envelope.source, envelope.timestamp.toNumber());
                 if (e.name === 'IncomingIdentityKeyError') {
                     message.save({ errors : [e] }).then(function() {
-                        extension.trigger('updateInbox');
+                        updateInbox();
                         notifyConversation(message);
                     });
                     return;
                 } else if (e.message !== 'Bad MAC') {
                     message.save({ errors : [ _.pick(e, ['name', 'message'])]}).then(function() {
-                        extension.trigger('updateInbox');
+                        updateInbox();
                         notifyConversation(message);
                     });
                     return;

js/models/conversations.js

@@ -84,7 +84,7 @@
             timestamp   : now,
             lastMessage : body
         }).then(function() {
-            extension.trigger('updateInbox'); // inbox fetch
+            updateInbox();
         });
 
         var sendFunc;
@@ -108,7 +108,7 @@
             });
             if (keyErrors.length) {
                 message.save({ errors : keyErrors }).then(function() {
-                    extension.trigger('updateInbox'); // notify frontend listeners
+                    updateInbox();
                 });
             } else {
                 if (!(errors instanceof Array)) {
@@ -188,7 +188,7 @@
         _.each(models, function(message) { message.destroy(); });
         this.archive();
         return this.save().then(function() {
-            extension.trigger('updateInbox');
+            updateInbox();
         });
     },
 

js/models/messages.js

@@ -218,7 +218,7 @@
 
                 conversation.save().then(function() {
                     message.save().then(function() {
-                        extension.trigger('updateInbox'); // inbox fetch
+                        updateInbox();
                         if (message.isIncoming()) {
                             notifyConversation(message);
                         } else {

js/panel_controller.js

@@ -41,15 +41,14 @@
         }
     });
 
-    function updateInbox() {
+    window.updateInbox = function() {
         conversations.fetchActive().then(function() {
             inbox.reset(conversations.filter(function(model) {
                 return model.get('active_at');
             }));
         });
-    }
+    };
 
-    extension.on('updateInbox', updateInbox);
     updateInbox();
     setUnreadCount(storage.get("unreadCount", 0));