Increase FidoNet echo/area tag max length from 40/50 to 60 chars

Update to commit 85a2de04 (2 years ago).

FSC-74 specifies:
"The conference name shall be no more than 60 characters in length."

SCFG was limiting sub and dir area-tags to 40 chars and SBBSecho was limiting
area tags to 50 chars in length.

FSC-74 isn't a standard, but lacking this detail in FTS-4 and considering it
comes from the same authoritative source (the Conference Mail System User
Manual), I think it's the best source of truth we have.

Also, since we're no longer using .cnf files, we don't need different max
area-tag lengths between SBBSecho and SCFG structs - they all now use the same
macro: FIDO_AREATAG_LEN

src/sbbs3/fidodefs.h

@@ -40,7 +40,7 @@
 #define FIDO_PASS_LEN			8	/* May NOT include '\0' terminator		*/
 #define FIDO_DOMAIN_LEN			8	/* May NOT include '\0' terminator		*/
 #define FIDO_PRODDATA_LEN		4	/* Product-specific Data */
-#define FIDO_AREATAG_LEN		50	// Echo "area tag" (NOT including '\0') (see FMail.txt)
+#define FIDO_AREATAG_LEN		60	// Echo "area tag" (NOT including '\0') (see FSC-74)
 #define FIDO_ECHO_TITLE_LEN		55	// Brief echo description, per echobase.hlp
 #define FIDO_ORIGIN_PREFIX_LEN	12	/* Includes new-line character			*/
 

src/sbbs3/scfgdefs.h

@@ -40,7 +40,7 @@ typedef struct {							/* Message sub board info */
 				post_sem[LEN_DIR+1],		/* Semaphore file for this sub */
 				tagline[81],				/* Optional QWK net tag line */
 				newsgroup[LEN_DIR+1];		/* Newsgroup name */
-	char		area_tag[41];
+	char		area_tag[FIDO_AREATAG_LEN+1];
 	uchar		ar[LEN_ARSTR+1],
 				read_ar[LEN_ARSTR+1],
 				post_ar[LEN_ARSTR+1],
@@ -74,7 +74,7 @@ typedef struct {							/* Transfer Directory Info */
 	char		code[LEN_EXTCODE+1];		/* Internal code (with optional lib prefix) */
 	char		code_suffix[LEN_CODE+1];	/* Eight character code suffix */
 	char		vdir[LEN_SLNAME+1];			/* Virtual Directory name */
-	char		area_tag[41];
+	char		area_tag[FIDO_AREATAG_LEN+1];
 	char		lname[LEN_SLNAME+1],		/* Long name - used for listing */
 				sname[LEN_SSNAME+1],		/* Short name - used for prompts */
 				arstr[LEN_ARSTR+1],			/* Access Requirements */