Update to iOS sdk 4.0.0.
Updated changelog, updated iOS library to 4.0.0
Make minimum cordova version to 3.4.1 to support iOS arm64 by default.
Updated ios library to 4.0.0 and docs.
Updated to android 4.0.1 sdk.
Update readme.
Replaced deprecated UARegistrationObservers methods with UARegistrationDelegate methods.
Check for device token and only raise registration if it exist.
Merge pull request #85 from urbanairship/MB-266

MB-266: Update Phonegap for iOS SDK 4.0.0 and Android SDK 4.0.1