Update README.md
Update README.md
Update README.md
Update README.md
init XHMessageBubbleFactory/XHMessageAvatorFactory
Merge pull request #1 from Aevit/master

calculate the height of textview for iOS7
fix the bug with scrollToBottomAnimated method
Add buttons to input view.
delete xib file,add annotation to inputView layout
delete xib file
add ENUM to Factorys
Finish Factory Method IMP, Add UIImage Category.

1、Add png files
2、Add Demo Example
Add mediaType property to message model.

1、change ENUM Text position
Add properties due with user avatar
Add DataSource Control method
Change mechanism.
Add property to block.

change the cell style code.
Update README.md
Add localString and UIGestureRecognizer.

1、Add Long Gesture control show the Menu
2、Add Tap GesTure control hide the Menu
3、Add background png
4、fix https://github.com/xhzengAIB/MessageDisplayKit/issues/2
delete png file