CB-5105 (Remove dead code for device.version)

Dead code has been removed for the following platforms:
-Android
-WP8
-BB10
-Windows 8
Every variable, method or argument related with retrieve the cordova
version from the native side has been removed. Given the fact that
cordova.js, it's providing the cordova.version.

The plugin has been tested under each platform involved with the
expected results, everything settled to be added to the repository.