Enrich WP8 support

It is consistent with existing Cordova SQLite plugins for iOS and Android. Also has fixes concerning synchronization. It uses json.net for serizlization of dynamic objects. Мove the logic for the dataconnection object in the executesqlbatch only. Extract all native into one dll.

Update plugins.xml to use framework element for WP8.

Thanks to https://github.com/brodybits/Cordova-SQLitePlugin-WP-2014.01 .