dosutils: add RIGHTS and finish Novell-style display fixes

- add RIGHTS as a new multi-call DOS utility
- implement Client32 NCP87 effective-rights query helper
- map NCP effective-rights bits to Novell RIGHTS display order
- keep legacy directory-handle based rights lookup as fallback
- match Novell RIGHTS output for directories and files more closely
- remove hardcoded MARS/SYS and SYS display fallbacks from RIGHTS/FLAGDIR
- derive display prefixes from the active network drive where available
- adjust FLAGDIR output formatting to match Novell field alignment
- keep FLAG and SLIST unchanged after checking for hardcoded prefixes

net.c

@@ -36,6 +36,7 @@ static struct s_net_functions {
 {"LOGOUT", "logout from server",       		    func_logout , 0},
 {"FLAG",   "display or modify file attributes",     func_flag   , 0},
 {"FLAGDIR","display or modify directory attributes",func_flagdir, 0},
+{"RIGHTS", "display effective file/directory rights",func_rights, 0},
 {"SLIST",  "list servers",          		    func_slist  , 0},
 {"PASSWD", "change password",          		    func_passwd , 0},
 #if 1