There are two main reasons for this change: by default, logback uses
stdout (!) and not stderr. This caused problems in programs like
packclass/unpackclass, where the packclass or JAR files were mixed in
with Netty's debug logging.
Secondly, the debug logging from lots of third-party libraries was
annoying (as it made it difficult to pick out OpenRS2-specific log
messages), so I've disabled lots of it.
Signed-off-by: Graham <gpe@openrs2.org>