Port Tux Paint to Android based on SDL2 template project and NDK

by Jianwei for Tux4Kids

Current Tux Paint is successfully ported from SDL1.2 to SDL2 by developers. Further porting it into Android platform can make it more interesting and welcomed. This proposal is to show how to port current tux-paint-sdl2 code to Android. Based on Android template project provided by SDL2 and Android NDK, we can directly use current C implementation without modifying current implementation too much, which is quite helpful for maintain and develop.