ext/ogg/gstoggmux.c (GstOggPad): Keep track of both the start time and the end time of the last packet in the page.

Original commit message from CVS:
2006-02-09  Andy Wingo  <wingo@pobox.com>

* ext/ogg/gstoggmux.c (GstOggPad): Keep track of both the start
time and the end time of the last packet in the page.
(gst_ogg_mux_pad_queue_page): In addition to setting the timestamp
on the pages in our queue, set the duration as well. Reflow a
debug statement.
(gst_ogg_mux_collected): Keep track of GstOggPad->timestamp_end.
Fixes bad muxing order.