tests: bin/header_keeper
gcc -E /usr/include/SDL/SDL_image.h | bin/header_keeper SDL_image.h
gcc -E /usr/include/GLES2/gl2.h | bin/header_keeper gl2.h
tests: bin/header_keeper
gcc -E /usr/include/SDL/SDL_image.h | bin/header_keeper SDL_image.h
gcc -E /usr/include/GLES2/gl2.h | bin/header_keeper gl2.h