how to customize UITabnar
===

How to customize UITabBarController to have something like this: 

![enter image description here][1]


  [1]: http://i.stack.imgur.com/HoHDC.png



In its normal state, it just looks like a normal UItabbar control with a more button (the area enclosed in red rectangle). When users click more button the second row is shown up like in the image.

