gst/audioresample/gstaudioresample.c: Don't trigger discontinuities for very small imperfections; a filter flush will...

Original commit message from CVS:
* gst/audioresample/gstaudioresample.c:
(audioresample_check_discont), (audioresample_transform):
Don't trigger discontinuities for very small imperfections; a filter
flush will sound bad, and many plugins have rounding errors leading
to these.