glsl 4.60 scheme for programmer's notepad 2.3

it has almost everything, but on purpose.
the layout keywords are missing, because the lexer treats them like any other keyword, so it highlights them even outside of the layout() qualifier, which may be confusing, because there they wouldn't be conflicting with anything.
the gl_Min* and gl_Max* constants are superfluous to highlight for most people, so i decided to omit them just to save memory :p