ext/ogg/gstoggmux.c: Forward port rewrite of muxing strategy to 0.9 version of oggmux.

ext/ogg/gstoggmux.c: Forward port rewrite of muxing strategy to 0.9 version of oggmux.

Original commit message from CVS:
* ext/ogg/gstoggmux.c: (gst_ogg_mux_request_new_pad),
(gst_ogg_mux_buffer_from_page), (gst_ogg_mux_push_buffer),
(gst_ogg_mux_dequeue_page), (gst_ogg_mux_pad_queue_page),
(gst_ogg_mux_send_headers), (gst_ogg_mux_collected):
Forward port rewrite of muxing strategy to 0.9 version of oggmux.
This makes us mux things correctly according to the ogg muxing
rules. Still not handling EOS correctly right now, though.