docs/design/part-TODO.txt: Updated TODO list, basesrc supports seeking to non-bytes...

docs/design/part-TODO.txt: Updated TODO list, basesrc supports seeking to non-bytes formats.

Original commit message from CVS:
* docs/design/part-TODO.txt:
Updated TODO list, basesrc supports seeking to non-bytes
formats.

* docs/design/part-element-sink.txt:
Update docs.

* gst/gstbin.c: (bin_replace_message),
(gst_bin_handle_message_func):
* gst/gstbus.c: (gst_bus_post), (gst_bus_pop):
* gst/gstevent.c: (gst_event_finalize):
* gst/gstpad.c: (gst_pad_event_default_dispatch),
(gst_pad_send_event):
Use shiny new _TYPE_NAME macros.

* libs/gst/base/gstbasesrc.c: (gst_base_src_get_range):
Move debug statement up.

* gst/gstelement.c: (gst_element_set_locked_state):
Add some debugging.