gst/flv/gstflvparse.c: Correct caps for video codec id 5: It's On2 VP6 with alpha...

gst/flv/gstflvparse.c: Correct caps for video codec id 5: It's On2 VP6 with alpha channel which needs a different dec...

Original commit message from CVS:
* gst/flv/gstflvparse.c: (gst_flv_parse_audio_negotiate),
(gst_flv_parse_tag_audio), (gst_flv_parse_video_negotiate):
Correct caps for video codec id 5: It's On2 VP6 with alpha channel
which needs a different decoder and has different caps.
Add support for audio codec id 14, which is MP3 with 8kHz sampling
rate.
Fix endianness and signedness for raw audio codec ids.
Add support for alaw and mulaw audio.