Change all the post processing shaders to the new system.

Removes the README.txt file in favour of a new wiki page I'm going to generate.

Data/Sys/Shaders/swap_RGB_BGR.glsl

@@ -1,9 +1,4 @@
-SAMPLER_BINDING(9) uniform sampler2D samp9;
-
-out vec4 ocol0;
-in vec2 uv0;
-
 void main()
 {
-	ocol0 = texture(samp9, uv0).bgra;
+	SetOutput(Sample().bgra);
 }