Refactor components for the main content section

Each conversation views now manages its own separate elements
rather than all binding to a shared #conversation element, and
similarly for message composition ui.

Also includes the beginnings of group creation UI (not working yet),
featuring bootstrap-tagsinput field for entering group recipients

js/models/threads.js

@@ -21,7 +21,15 @@ var Whisper = Whisper || {};
     },
 
     sendMessage: function(message) {
-      var m = Whisper.Messages.addOutgoingMessage(message, this);
+      this.messages().add({ type: 'outgoing',
+                            body: message,
+                            threadId: this.id,
+                            timestamp: new Date().getTime() }).save();
+
+      this.save({ timestamp:   new Date().getTime(),
+                  unreadCount: 0,
+                  active:      true});
+
       if (this.get('type') == 'private') {
         var promise = textsecure.messaging.sendMessageToNumber(this.get('id'), message, []);
       }
@@ -57,6 +65,18 @@ var Whisper = Whisper || {};
       return thread;
     },
 
+    createGroup: function(recipients, name) {
+      var group = textsecure.storage.groups.createNewGroup(numbers);
+      var attributes = {};
+      attributes = {
+        id        : group.id,
+        name      : name,
+        numbers   : group.numbers,
+        type      : 'group',
+      };
+      return this.findOrCreate(attributes);
+    },
+
     findOrCreateForRecipient: function(recipient) {
       var attributes = {};
       attributes = {