This fixes stats.xml listings for mp3 slave relays with metadata.
We get rid of 'metadata_raw', since we now have to format out that stuff anyway.
svn path=/trunk/icecast/; revision=5815
a) based on total bytes in queue, not total number of buffers in queue
b) configurable (defaults to 100 kB)
mp3 metadata relaying (inline). Untested.
svn path=/trunk/icecast/; revision=4364