Reserve UID 125 and GIDs 125 and 126 for Postfix.

This commit also adds an incomplete list of reserved GIDs, because some
ports use GIDs that have no corresponding user.  I've listed GIDs that are
in the stock groups file as well as those used by ports which I myself use.

en_US.ISO8859-1/books/porters-handbook/book.sgml

@@ -6400,8 +6400,9 @@ lib/X11/oneko/sounds/cat.au
 	  <filename role="package">japanese/Wnn6</filename> for an example.</para>
 
 	<para>Make sure you do not use a UID already used by the system or
-	  other ports.  This is the current list of UIDs between 50 and
-	  999.</para>
+	  other ports.</para>
+
+        <para>This is the current list of UIDs between 50 and 999.</para>
 
 	<!-- Please keep this list sorted by uid -->
 	<programlisting>bind:*:53:53:Bind Sandbox:/:/sbin/nologin
@@ -6443,11 +6444,29 @@ quagga:*:101:101:Quagga route daemon pseudo user:/usr/local/etc/quagga:/sbin/nol
 ganglia:*:102:102:Ganglia User:/nonexistent:/sbin/nologin
 sgeadmin:*:103:103:Sun Grid Engine Admin:/nonexistent:/sbin/nologin
 fido:*:111:111:Fido System:/usr/local/fido:/bin/sh
+postfix:*:125:125:Postfix Mail System:/var/spool/postfix:/sbin/nologin
 agk:*:172:172:AquaGateKeeper:/nonexistent:/nonexistent
 ldap:*:389:389:OpenLDAP Server:/nonexistent:/sbin/nologin
 drweb:*:426:426:Dr.Web Mail Scanner:/nonexistent:/sbin/nologin
 bacula:*:910:910:Bacula Daemon:/var/db/bacula:/sbin/nologin</programlisting>
 
+	<para>This is the current list of reserved GIDs.</para>
+
+	<!-- Please keep this list sorted by uid -->
+	<!-- XXX incomplete! -->
+	<programlisting>bind:*:53:
+cyrus:*:60:
+proxy:*:62:
+authpf:*:63:
+uucp:*:66:
+dialer:*:68:
+network:*:69:
+pgsql:*:70:
+www:*:80:
+mailman:*:91:
+postfix:*:125:
+maildrop:*:126:</programlisting>
+
 	<para>Please include a notice when you submit a port (or an upgrade)
 	  that reserves a new UID or GID in this range.  This allows us to
 	  keep the list of reserved IDs up to date.</para>