Swipetweet

Swipe when tweet

* removes tweet button from NewTweetPage and use swipe since more logic in sailfish UI 
* Page => Dialog
* Move "posttweet" logic to main.qml instead of NewTweetPage because page is destroyed onAccept
* rename internal => tweetInternal to not conflict with other pages since object is now global.
* Dont show New Tweet Pulley menu when pending tweet
* pageStack.push again if tweet fails.

Tested:

 reply, new and image (with normal twitter upload) is tested