Created toggle option (XTRN_NO_MUTEX) for new xtrn_misc scfg_t property.

src/sbbs3/sbbsdefs.h

@@ -387,6 +387,9 @@ typedef enum {						/* Values for xtrn_t.event			*/
 #define STRIPKLUDGE (1L<<15)		/* Strip FTN Kludge lines from msg		*/
 #define XTRN_CHKTIME (1<<16)		/* Check time online (EX_CHKTIME)		*/
 
+									/* Bits in cfg.xtrn_misc				*/
+#define XTRN_NO_MUTEX	(1<<0)		/* Do not use exec_mutex for FOSSIL VXD	*/
+
 									/* Bits in user.qwk 					*/
 #define QWK_FILES	(1L<<0) 		/* Include new files list				*/
 #define QWK_EMAIL	(1L<<1) 		/* Include unread e-mail				*/