Implements a Client capable of searching for Services and Devices and of handling incoming notifications.

The DefaultClient class implements the interfaces DeviceListener, ClientListener, EventListener but only provides empty callback methods and should therefore be extended and those methods overwritten to handle callbacks in the desired way. Instances of DefaultClient can search for devices or services matching a given SearchParameter argument. SearchCallback instances provide a receiver for search matches, and can handle deviceFound/serviceFound notifications, whilst the actual search is taken care of by the SearchManager class.