A way to reuse a buffer when reading `.gif` files

[sam20908]

A way to reuse a buffer when reading `.gif` files

[nothings]

The plan is to remove all support for animated gifs from stb_image and fork them into a separate library (which I personally will not be maintaing), because this has just been a source of headaches and it's really outside the original intent of stb_image.

[DavinPride]

gif = stbi_load_gif_v2("filename.gif", ...);
unsigned char buffer[...];
while (stbi_gif_has_frame(gif)) {
error = stbi_gif_decode_frame(gif, buffer);
// do something with buffer if no error occurred
stbi_gif_advance_frame(gif);
}