gst/gstbus.c (gst_bus_class_init): Declare our private data structure.

gst/gstbus.c (gst_bus_class_init): Declare our private data structure.

Original commit message from CVS:
2006-02-10  Andy Wingo  <wingo@pobox.com>

* gst/gstbus.c (gst_bus_class_init): Declare our private data
structure.
(gst_bus_init): Cache the location of the private data in the
instance structure.
(gst_bus_enable_sync_message_emission)
(gst_bus_disable_sync_message_emission): Implement new public
functions.
(gst_bus_post): Emit the sync-message signal if the user asked for
it. Fixes #330684.

* gst/gstbus.h (GstBus): Use a padding pointer to cache the
location of the bus-private structuure.
(gst_bus_enable_sync_message_emission)
(gst_bus_disable_sync_message_emission): New public functions.