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/flag.h

@@ -201,6 +201,7 @@ struct instance_flags {
 	boolean  rlecomp;	/* run-length comp of levels when writing savefile */
 	uchar	 num_pad_mode;
 	boolean  echo;		/* 1 to echo characters */
+	boolean use_menu_color;	/* use color in menus; only if wc_color */
 #if 0
 	boolean  DECgraphics;	/* use DEC VT-xxx extended character set */
 	boolean  IBMgraphics;	/* use IBM extended character set */