examples/: Update a couple of the examples to work again.

examples/: Update a couple of the examples to work again.

Original commit message from CVS:
* examples/Makefile.am:
* examples/helloworld/helloworld.c: (event_loop), (main):
* examples/queue/queue.c: (event_loop), (main):
* examples/queue2/queue2.c: (main):
Update a couple of the examples to work again.

* gst/base/gstbasesink.c: (gst_base_sink_preroll_queue_empty),
(gst_base_sink_preroll_queue_flush), (gst_base_sink_handle_event):
Spelling corrections and extra debug.

* gst/gstbin.c: (gst_bin_class_init), (gst_bin_init), (is_eos),
(gst_bin_add_func), (bin_element_is_sink), (gst_bin_get_state),
(gst_bin_change_state), (gst_bin_dispose), (bin_bus_handler):
* gst/gstbin.h:
* gst/gstpipeline.c: (gst_pipeline_init), (gst_pipeline_dispose),
(gst_pipeline_change_state):
* gst/gstpipeline.h:
Move the bus handler for children to the GstBin, and create a
separate bus for receiving messages from children to the one the
bus sends 'upwards' on.