Remove GPeriodic for now

The necessary review and integration work has not happened, and
we don't want to enshrine it in this unproven state.
It will be back when the world is ready for it.

docs/reference/gio/gio-docs.xml

@@ -184,10 +184,6 @@
         <xi:include href="xml/gapplication.xml"/>
         <xi:include href="xml/gapplicationcommandline.xml"/>
     </chapter>
-    <chapter id="periodic">
-        <title>Periodic Timer</title>
-        <xi:include href="xml/gperiodic.xml"/>
-    </chapter>
     <chapter id="extending">
         <title>Extending GIO</title>
         <xi:include href="xml/gvfs.xml"/>

docs/reference/gio/gio-sections.txt

@@ -2936,32 +2936,6 @@ G_TYPE_PROXY
 g_proxy_get_type
 </SECTION>
 
-<SECTION>
-<FILE>gperiodic</FILE>
-<TITLE>GPeriodic</TITLE>
-GPeriodic
-<SUBSECTION>
-g_periodic_new
-g_periodic_get_hz
-g_periodic_get_high_priority
-g_periodic_get_low_priority
-<SUBSECTION>
-GPeriodicTickFunc
-g_periodic_add
-g_periodic_remove
-<SUBSECTION>
-g_periodic_block
-g_periodic_unblock
-<SUBSECTION>
-g_periodic_damaged
-<SUBSECTION Standard>
-G_TYPE_PERIODIC
-G_PERIODIC
-G_IS_PERIODIC
-<SUBSECTION Private>
-g_periodic_get_type
-</SECTION>
-
 <SECTION>
 <FILE>gpollableinputstream</FILE>
 <TITLE>GPollableInputStream</TITLE>

docs/reference/gio/gio.types

@@ -74,7 +74,6 @@ g_network_service_get_type
 g_output_stream_get_type
 g_output_stream_splice_flags_get_type
 g_password_save_get_type
-g_periodic_get_type
 g_permission_get_type
 g_pollable_input_stream_get_type
 g_pollable_output_stream_get_type