Icon support and bug fixes

* Now parses GCM message for smallIcon, largeIcon, bigPicture, and action button icon support.

* Fixed build issue when Facebook plugin was included or any other plugin using the Android Support Library v4 or v11.
* Now holds onto the last 10 notification ids and if the device receives a duplicate it omits it.
  - Reinstalling the app may create extra Google registration ids which was creating the issue in the first place.
* Handles malformed GCM data correctly.
* Now omits common invalid phone ids so a possible good Android id or wifi mac can be used.
* Updated license