Added support for CocoaPods

I've added preliminary support for [CocoaPods](http://cocoapods.org/). Please review the podspec file and submit it to the master CocoaPods repository. See http://docs.cocoapods.org/guides/contributing_to_the_master_repo.html for more details.

To make the pod work for my project, I've had to make changes in NotificareMKNetworkKit.h. The paths that were included in the #import statements caused the project to break, and the definition of DLog, ELog and ALog macros made some warnings show up, because I had already defined those macros elsewhere in the project. Right now I have simply undefined them, but these macros should probably be removed from the push library altogether.