check/: I wrote a test!

check/: I wrote a test!

Original commit message from CVS:
* check/Makefile.am:
* check/gst/gstevents.c: (GST_START_TEST), (event_probe),
(test_event), (timediff), (gstevents_suite), (main):
I wrote a test!

* docs/design/part-seeking.txt:
Spelling correction

* docs/gst/tmpl/gstevent.sgml:
Docs updates.

* gst/base/gstbasesink.c: (gst_base_sink_handle_object):
Treat a buffer-without-newsegment the same as a receiving
a newsegment not in time format, and disable syncing to the clock
with a warning.

* gst/gstbus.c: (gst_bus_set_sync_handler):
Assert if anyone tries to replace the existing sync_handler for bus,
as only the owner should be setting it.

* gst/gstevent.h:
Have a fixed set of custom event enums with events identified by
their structure name (as in 0.8), rather than a free-for-all
allowing collisions between enum values from different plugins.

* gst/gstpad.c: (gst_pad_class_init):
Docs change.

* gst/gstqueue.c: (gst_queue_handle_sink_event):
Handle out-of-band downstream events from the sending thread.