bug fix: possible duplicate tweet
improve user experience

Play gif in PictureViewer
bug fix: duplicate tweets when turning to next page
AbstractTweetContainer created

AbstractTweetContainer: abstract widget for tweets and mentions
AtWidget finished
add CommentWidget
SendRecomment

1. add SendRecomment
2. adjust PictureViewer with the same top of main window
repost tweet while commenting

Repost comment while commenting
Repost retweet while commenting
Merge branch 'dev'