Original commit message from CVS:

* check/elements/level.c: (GST_START_TEST):
fix test for new GstClockTime use
* gst/level/gstlevel.c: (gst_level_init), (gst_level_set_caps),
(gst_level_transform_ip):
* gst/level/gstlevel.h:
fix up the decay peak, ensuring the decay peak is never lower
than the peak for that interval