Original commit message from CVS:
* check/gst/gstbin.c: (GST_START_TEST):
Enable check that works now.

* gst/gstbin.c: (add_to_queue), (clear_queue), (reset_outdegree),
(update_outdegree), (find_element), (gst_bin_sort_iterator_next),
(gst_bin_sort_iterator_resync), (gst_bin_sort_iterator_free),
(gst_bin_iterate_sorted), (gst_bin_element_set_state),
(gst_bin_change_state):
* gst/gstbin.h:
Redid the state change algorithm using a topological sort algo.
Handles all cases correctly.
Exposed iterator for state change order.

* gst/gstelement.h:
Temp storage for state changes. Need to get rid of this soon.