Add menucolors

-Add a boolean option menucolors to toggle menu color
-Add MENUCOLOR -config file option

TODO:
-Better support for win32
-Support more windowports
-Update Guidebook
-Allow changing menucolor lines in-game

include/extern.h

@@ -1583,6 +1583,9 @@ E void FDECL(parsesymbols, (char *));
 E struct symparse *FDECL(match_sym, (char *));
 E void NDECL(set_playmode);
 E int FDECL(sym_val, (char *));
+E boolean FDECL(add_menu_coloring, (char *));
+E boolean FDECL(get_menu_coloring, (char *, int *, int *));
+E void NDECL(free_menu_coloring);
 
 /* ### pager.c ### */