Support auto-resizing on rotations, fix #18

@bmnick Can you take a look? :smile_cat:

Here's a gif with color blender layers if you want to see it in action:
![Demo](http://i.imgur.com/EVlE7QT.gif)

Yup, currently(with this commit) if you layout the textfield using autolayout, it will loop infinitely between layoutSubview and layoutTokensAndInput.
Plus, it doesn't quite work with autolayout yet. 
But, we can fix that problem once this is merged.