sync up to kh16. A fair bit of this is the format api changes to allow for

use by the file handles, and some compile-time debug code to check for memory
usage.

. We can now fall back to file again without the original stream being present.
. Listener specific intro content can now come via auth listener_add.
. The relay updates for the retry, timeout and disable settings were missed


svn path=/icecast/branches/kh/icecast/; revision=16593