AFSwiftDateExtensionNSDate 扩展

AFSwiftDateExtension 是 iOS NSDate 扩展，能使 NSDate 相关操作更简单，它依靠 SWIFT 顶层函数建立，有更好的体验和安全性。

特性：

• Compare dates using common compare operators: >, >=, <, <=

• Get interval between dates using that custom operator >-<

• Add/remove date components by using aritmethic operators: +, -, +=, -=

• Curryed functions

• Use subscripting to access single or group of date components

要求：

• iOS7 or above

• Swift 1.2