man: don't include history sections in man pages

I am pretty sure we shouldn't carry history sections in man pages, since it's
very hard to keep them correctly updated, the current ones are very
out-of-date, and they tend to make APIs appear unnecessarily complex.

man/sd_journal_open.xml

@@ -204,26 +204,6 @@
     file.</para>
   </refsect1>
 
-  <refsect1>
-    <title>History</title>
-
-    <para><function>sd_journal_open()</function>,
-    <function>sd_journal_close()</function>,
-    <constant>SD_JOURNAL_LOCAL_ONLY</constant>,
-    <constant>SD_JOURNAL_RUNTIME_ONLY</constant>,
-    <constant>SD_JOURNAL_SYSTEM_ONLY</constant> were added in
-    systemd-38.</para>
-
-    <para><function>sd_journal_open_directory()</function> was added
-    in systemd-187.</para>
-
-    <para><constant>SD_JOURNAL_SYSTEM</constant>,
-    <constant>SD_JOURNAL_CURRENT_USER</constant>, and
-    <function>sd_journal_open_files()</function> were added in
-    systemd-205. <constant>SD_JOURNAL_SYSTEM_ONLY</constant> was
-    deprecated.</para>
-  </refsect1>
-
   <refsect1>
     <title>See Also</title>
 

man/sd_uid_get_state.xml

@@ -217,19 +217,6 @@
     entry.</para>
   </refsect1>
 
-  <refsect1>
-    <title>History</title>
-
-    <para><function>sd_uid_get_state()</function>,
-    <function>sd_uid_is_on_seat()</function>,
-    <function>sd_uid_get_sessions()</function>, and
-    <function>sd_uid_get_seats()</function> functions were added in
-    systemd-31.</para>
-
-    <para><function>sd_uid_get_display()</function> was added in
-    systemd-213.</para>
-  </refsect1>
-
   <refsect1>
     <title>See Also</title>
 

man/sd_watchdog_enabled.xml

@@ -154,18 +154,6 @@
     </variablelist>
   </refsect1>
 
-  <refsect1>
-    <title>History</title>
-
-    <para>The watchdog functionality and the
-    <varname>$WATCHDOG_USEC</varname> variable were added in
-    systemd-41.</para>
-
-    <para><function>sd_watchdog_enabled()</function> function was
-    added in systemd-209. Since that version, the
-    <varname>$WATCHDOG_PID</varname> variable is also set.</para>
-  </refsect1>
-
   <refsect1>
     <title>See Also</title>
     <para>