check/gst/gstbin.c: Add bus to bin.

check/gst/gstbin.c: Add bus to bin.

Original commit message from CVS:
* check/gst/gstbin.c: (GST_START_TEST):
Add bus to bin.

* gst/gstbin.c: (gst_bin_class_init), (gst_bin_init),
(add_to_queue), (clear_queue), (reset_degree), (update_degree),
(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_bin_dispose):
A bin does not have a bus, it gets the bus from the parent.

* gst/gstelement.c: (gst_element_requires_clock),
(gst_element_provides_clock), (gst_element_is_indexable),
(gst_element_is_locked_state), (gst_element_change_state),
(gst_element_set_bus_func):
Small cleanups.

* gst/gstpipeline.c: (gst_pipeline_class_init),
(gst_pipeline_init), (gst_pipeline_provide_clock_func):
The pipeline provides a bus.