icecast-2.4.0-kh21.7

various fixes from reports. Use 21.8 instead

fix issue on stream auth from previous pre-release
added listenurl tag (per-mount) for people wanting to try out, for YP only really.
improve internal handling for range handling and how it ties into keep alive.
worker client process limiter was too high
safari handling should be better now, and not clash with other browsers.
fix lock imbalance in fserve handling

karl