#MultiLayerNavigation
##介绍 / Introduction
MultiLayerNavigation可以让你轻易地实现类似网易新闻/新浪微博滑动返回的交互效果；
你唯一需要做的就是把UINavigationController替换为MLNavigationController，或者继承它；
MultiLayerNavigation helps you implemntation the interaction -- 'drag to back' in a easy way.
The only one thing you need to do is replacing your UINavigationController with the MLNavigation Controller or inheriting it.
##已知问题
- 只能使用push/pop系列方法来切换viewcontroller,不能直接调用setViewControllers设置;
##Known Issues
- NOT support using setViewControllers method to swicth viewcontroller.