`Threads.createThreadMockup(...)` => `Thread.create(...)`

`Thread.create` should do: 

```js

Thread.create = function(message, options) {   
  // Given a message we create a thread as a mockup. This let us render the
  // thread without requesting Gecko, so we increase the performance and we
  // reduce Gecko requests.
  return new Thread({
    id: message.threadId,
    participants: [message.sender || message.receiver],
    body: message.body,
    timestamp: message.timestamp,
    unreadCount: (options && !options.read) ? 1 : 0,
    lastMessageType: message.type || 'sms'
  });
};


```