Original commit message from CVS:
2005-11-15  Andy Wingo  <wingo@pobox.com>

* gst/gstelement.c (gst_element_set_base_time): Add debugging.

* gst/gstpipeline.c (gst_pipeline_set_new_stream_time): Document
using GST_CLOCK_TIME_NONE to disable base time management.
(do_pipeline_seek, gst_pipeline_change_state): Don't reset stream
time if it was NONE before.
(gst_pipeline_change_state): Only munge the base time if
stream_time != GST_CLOCK_TIME_NONE.

* check/gst/gstpipeline.c (test_base_time): Punt around the
problem of the probe not being called, because that's not the
issue I'm looking at. Add a check that setting stream_time to NONE
disables base time management.