New settings in game configurations

General settings:

basegame - indicates which game the current configuration is based on. Used to load game-specific GLDEFS lumps (DOOMDEFS, HTICDEFS, HEXNDEFS or STRFDEFS)
Possible values: 1 (DOOM), 2 (HERETIC), 3 (HEXEN) or 4 (STRIFE).
Example: basegame = 2;

Thing and linedef definitions:

Default values can be set in Thing and Linedef argument definitions.
Example:
9038
{
    title = "ColorSetter";
    arg0
    {
        title = "Red";
        default = 255;
    }
    arg1
    {
        title = "Green";
        default = 255;
    }
    arg2
    {
        title = "Blue";
        default = 255;
    }
    arg3
    {
        title = "Desaturation";
    }
}