Original commit message from CVS:
2005-11-29  Andy Wingo  <wingo@pobox.com>

* gst/gstevent.h (struct _GstEvent): Only one pointer of padding.

* gst/gststructure.h (struct _GstStructure): Only one pointer of
padding.

* gst/gstquery.h (struct _GstQuery): Only one pointer of padding.

* gst/gstpluginfeature.h: Remove a comment in PluginFeature.

* gst/gstplugin.h (struct _GstPluginClass): Add some padding.

* gst/gstobject.h: (struct _GstObject): Only one pointer of
padding; reduces object size by about 30%. We don't expect
anything else to go into gstobject.

* gst/gstminiobject.h (struct _GstMiniObject)
(struct _GstMiniObjectClass): Only one pointer of padding; the
payload is only a pointer and two ints anyway. For the class there
are only two methods as well.

* gst/gstelement.h (struct _GstElementClass): Removed
the state_changed signal callback, it is not used.