[icecast] import from old packages

Signed-off-by: André Gaul <gaul@web-yard.de>
[icecast] upgrade to 2.4.0

Signed-off-by: André Gaul <gaul@web-yard.de>
[icecast] add minimalistic init script

Signed-off-by: André Gaul <gaul@web-yard.de>