Changes

This shader is supposed to appear the same as nearest neighbor (aka "unfiltered"), except with minor corrections when using a non-integer scale that are increasingly less noticeable the higher it is scaled. This shader is useful to anyone who wants to keep things as sharp as possible without worrying about scale factors. Available in [https://github.com/hizzlekizzle/quark-shaders/tree/master/Pixellate.shader Quark] and [https://github.com/libretro/common-shaders/blob/master/retro/shaders/pixellate.cg Cg] shader formats. A newer alternative that does the same thing (but may give sharper results) is the sharp-bilinear shader, which prescales the image to a high resolution, then downscales using bilinear scaling.