Add new and documented api reported in -unused.txt to -section.txt.
GST_TAG_PUBLISHER
GST_TAG_INTERPRETED_BY
GST_TAG_MIDI_BASE_NOTE
+GST_TAG_PRIVATE_DATA
gst_tag_register
gst_tag_register_static
gst_device_monitor_start
gst_device_monitor_stop
gst_device_monitor_get_devices
+gst_device_monitor_get_providers
+gst_device_monitor_get_show_all_devices
+gst_device_monitor_set_show_all_devices
+gst_device_provider_get_hidden_providers
+gst_device_provider_hide_provider
+gst_device_provider_unhide_provider
<SUBSECTION Standard>
GstDeviceMonitorPrivate