gst/playback/gstdecodebin.c: Better use of the queues. Start with a small size queue and only increase the size of th...

Original commit message from CVS:
* gst/playback/gstdecodebin.c: (gst_decode_bin_init),
(try_to_link_1), (queue_filled_cb):
Better use of the queues. Start with a small size queue and only increase
the size of the queues when the other queues are empty.