push-sdk 'Swift' port

done for [AGIOS-219](https://issues.jboss.org/browse/AGIOS-219)

note: Xcode 6 beta-4 (latest) is required.

only if you want to contribute to push-sdk and add/run the tests target, for our users of the library this is not needed, they simply drag the source on their project as described in the README.md and that's sufficient.