system-wide configuration file

Add options SYSCF (to add a system-wide configuration file) and SYSCF_FILE
(for a file-based implementation of SYSCF) - this allows a binary distribution
to be configured at install time.  The only option supported at this time is
WIZARDS - a list of usernames which can use -D; currently only for unix-likes
but should be extendable to anything that has a concept of multiple users.
Add mac tty multiuser config using sgid.

src/decl.c

@@ -70,6 +70,9 @@ const char ynNaqchars[] = "yn#aq";
 NEARDATA long yn_number = 0L;
 
 const char disclosure_options[] = "iavgc";
+#ifdef SYSCF
+char wizards[PL_PSIZ] = DUMMY;
+#endif
 
 #if defined(MICRO) || defined(WIN32)
 char hackdir[PATHLEN];		/* where rumors, help, record are */