Updated project to Android Studio 2.2 and gradle

[oers]

As a first step to get Development started with the new Android Studio I updated the project layout to the new Android Studio 2.2.

This project will now work in Android Studio 2.2.

NDK is needed as an addition tool which mus be installed via the SDK manager,

[panstromek]

@alkom It would be nice if you merged and updated this in google play. I would also like to contribute, It's been some time since I implemented "One move practice mode" (zebra generates random board and you need to guess the best move), so if you guys would like it I could update it and submit PR, too. I also have some feature requests from friends that we could implement...