Consistently use NSInteger typedefs

`NSInteger` != `int` on all platforms; native types (e.g. `NSInteger`) should generally be preferred for platform agnostic code.

In particular, the library won't compile for armv64 because `EDServer`'s version properties are declared as `NSInteger` externally, but as `int` internally. Those are the same thing on 32-bit machine but not a 64-bit machine:

![screen shot 2014-01-13 at 3 20 40 pm](https://f.cloud.github.com/assets/141447/1905031/99a12456-7c98-11e3-9ddf-e33bae2b378f.png)

Thanks for the great little library!