Merge pull request #32 from Monroe88/master

(gameboy) Add a preset that uses the included Game Boy Pocket palette
Add Sp00kyFox's bilateral filtering shader
add leilei's gendither and move Sp00kyFox's bilateral from dithering to blurs, as requested
small tweak to some of my shaders to hopefully make them less tempermental
add crt-lottes shader based on https://www.shadertoy.com/view/XsjSzR# by
TIMOTHY LOTTES.
crt-lottes : remove unnecessary screen coordinates check, bit performance
gain.
Added brightness control to crt-lottes

It's just a multiplier added to the fetch() function's output, as described in one of Lottes' comments on the shadertoy page. I left the default at 1.0, since raising it can introduce color clipping.
update crt-easymode with dot-masks
Update crt-easymode to work on AMD GPUs
Uniquely name Jinc2 and Lanczos2 shader parameters.
Merge branch 'master' of https://github.com/libretro/common-shaders
Add a tvout preset that mimics sharp-bilinear with some color adjustments.
Add tvout presets that use Jinc to sharpen heavily blended output.