added shadownaemon tool

shadownaemon uses livestatus to create a shadow copy if a remote site which
then can be used to run livestatus queries against the local shadow copy.
While running it will update runtime data periodically. It therefor removes
network latency when connection to slow remote sites and it also reduces
bandwith usage when having lots of client connections.
Logfiles and commands are not supported and have to be queried directly via
the remote site.

Signed-off-by: Sven Nierlein <sven@nierlein.de>