Azure notification hub iOS (#14)

* Added initial framework.

* Added register and unregister for notifications.

* Refactored frameworks and dependencies.

* Refactored constant strings.

* Refactored project structure based on the PushNotificationIOS library.

* Updated error messages in addEventListener and removeEventListener methods.

Author: phongcao

index.ios.js

@@ -0,0 +1 @@
+module.exports = require('./ios/AzureNotificationHubIOS');