Additional pxboot features

[SpartanSf]

• Added entrycolor(foreground, background) configuration command

Allows setting custom foreground and background colors for individual menu entries, can be used within menuentry definitions

• Added entrybackground and entryforeground configuration options

Provides default colors for all entries when per-entry colors aren't specified

• args now supports function style arguments

Arguments can be passed in to args like a function, e.g.:
args("/sbin/init.lua", "--safe", "--no-gui");

Backwards compatibility has been maintained.

Example config file utilizing some of the new features:

defaultentry = "qkOS"
timeout = 5
backgroundcolor = colors.black
selectcolor = colors.orange
selecttext = colors.black
titlecolor = colors.lightGray
textcolor = colors.white

entrybackground = colors.black
entryforeground = colors.lightGray

menuentry "qkOS" {
    entrycolor(colors.yellow, colors.cyan);
    description "Boot qkOS normally.";
    kernel "/boot/kernel/kernel.lua";
    args("/sbin/init.lua");
}

menuentry "qkOS (Recovery)" {
    entrycolor(colors.yellow, colors.gray);
    description "Boot qkOS with minimal services.";
    kernel "/boot/kernel/kernel.lua";
    args("/sbin/init.lua", "--safe", "--no-gui");
}

menuentry "CraftOS" {
    description "Boot into CraftOS.";
    craftos;
}

include "config.lua.d/*"