Added ID function to router interface.
Network registry addresses are deregistered when the router is stopped.
Query has been updated to search for particular GW in lookups.
Router interface has been redefined which fits better with what we are
looking for.
Routing table now offers a comprehensive set of information about its
entries which will make up for rich queries in the future
Query interface has been defined to enable current basic and more
advanced queries in the future.
