gst/wavenc/gstwavenc.c: Added proper event handlind, made downstream newsegment event use GST_FORMAT_BYTES (otherwise...

Original commit message from CVS:
* gst/wavenc/gstwavenc.c: (gst_wavenc_stop_file),
(gst_wavenc_init), (gst_wavenc_event), (gst_wavenc_chain):
Added proper event handlind,
made downstream newsegment event use GST_FORMAT_BYTES (otherwise it's
ignored),
and don't set a duration of 0 for buffers otherwise they are discarded
by GstBaseSink.
GstWavEnc needs some serious loving, after going through the code I'm
really wondering how this can stay in -good ...