man: add version info

This tries to add information about when each option was added. It goes
back to version 183.

The version info is included from a separate file to allow generating it,
which would allow more control on the formatting of the final output.

man/systemd-socket-activate.xml

@@ -62,6 +62,8 @@
         <listitem><para>Listen on this <replaceable>address</replaceable>.
         Takes a string like <literal>2000</literal> or
         <literal>127.0.0.1:2001</literal>.</para>
+
+        <xi:include href="version-info.xml" xpointer="v230"/>
         </listitem>
       </varlistentry>
 
@@ -70,7 +72,9 @@
         <term><option>--accept</option></term>
 
         <listitem><para>Launch an instance of the service program for each connection and pass the connection
-        socket.</para></listitem>
+        socket.</para>
+
+        <xi:include href="version-info.xml" xpointer="v230"/></listitem>
       </varlistentry>
 
       <varlistentry>
@@ -78,7 +82,9 @@
         <term><option>--datagram</option></term>
 
         <listitem><para>Listen on a datagram socket (<constant>SOCK_DGRAM</constant>), instead of a stream socket
-        (<constant>SOCK_STREAM</constant>). May not be combined with <option>--seqpacket</option>.</para></listitem>
+        (<constant>SOCK_STREAM</constant>). May not be combined with <option>--seqpacket</option>.</para>
+
+        <xi:include href="version-info.xml" xpointer="v230"/></listitem>
       </varlistentry>
 
       <varlistentry>
@@ -86,7 +92,9 @@
 
         <listitem><para>Listen on a sequential packet socket (<constant>SOCK_SEQPACKET</constant>), instead of a stream
         socket (<constant>SOCK_STREAM</constant>). May not be combined with
-        <option>--datagram</option>.</para></listitem>
+        <option>--datagram</option>.</para>
+
+        <xi:include href="version-info.xml" xpointer="v230"/></listitem>
       </varlistentry>
 
       <varlistentry>
@@ -94,7 +102,9 @@
 
         <listitem><para>Use the inetd protocol for passing file descriptors, i.e. as standard input and standard
         output, instead of the new-style protocol for passing file descriptors using <varname>$LISTEN_FDS</varname>
-        (see above).</para></listitem>
+        (see above).</para>
+
+        <xi:include href="version-info.xml" xpointer="v230"/></listitem>
       </varlistentry>
 
       <varlistentry>
@@ -106,7 +116,9 @@
         followed by <literal>=</literal>, assume that it is a
         variable–value pair. Otherwise, obtain the value from the
         environment of <command>systemd-socket-activate</command> itself.
-        </para></listitem>
+        </para>
+
+        <xi:include href="version-info.xml" xpointer="v230"/></listitem>
       </varlistentry>
 
       <varlistentry>
@@ -118,7 +130,9 @@
         Multiple entries may be specifies using separate options or by separating names with colons
         (<literal>:</literal>) in one option. In case more names are given than descriptors, superfluous ones will be
         ignored. In case less names are given than descriptors, the remaining file descriptors will be unnamed.
-        </para></listitem>
+        </para>
+
+        <xi:include href="version-info.xml" xpointer="v233"/></listitem>
       </varlistentry>
 
       <xi:include href="standard-options.xml" xpointer="help" />
@@ -135,7 +149,9 @@
         <term><varname>$LISTEN_FDNAMES</varname></term>
 
         <listitem><para>See
-        <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem>
+        <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
+
+        <xi:include href="version-info.xml" xpointer="v230"/></listitem>
       </varlistentry>
 
       <varlistentry>