CMNavBarNotificationView应用内的提醒效果

CMNavBarNotificationView 实现了应用内的提醒效果，显示在导航条的顶部，如下图所示：

Features:

• Animation and layout similar to iOS 6 notifications

• Provides two UILabels and an UIImageView for customization

• Simple API

• Enqueues multiple notifications and shows them with a default duration of 2 seconds.

CMNavBarNotificationView 完全基于 MPNotificationView 进行扩展。