QOI support

[God-damnit-all]

The Quite OK Image Format (QOI) is does job of non-animated PNGs, but better. They're much smaller and they decrypt much faster. There's already many different implementations of it available. Relevant to this project, there's two done in C++ and two done in C:

https://github.com/shadowMitia/libqoi/ (C++) https://github.com/wx257osn2/qoixx (C++) https://github.com/superzazu/SDL_QOI (C, SDL2 bindings) https://github.com/shraiwi/mini-qoi (C, streaming decoder)

[phanirithvij]

The source implementation https://github.com/phoboslab/qoi is also in C