Updated stb-image from v0.94 to v1.00.
Updated stb-image from v0.94 to v1.00.

grimfang4/sdl-gpu,grimfang4/sdl-gpu,ademuri/sdl-gpu,ademuri/sdl-gpu,grimfang4/sdl-gpu,ademuri/sdl-gpu,ademuri/sdl-gpu,grimfang4/sdl-gpu