Host access security

The application is started with an access control string, which is a list of hosts it is prepared to accept commands from. It passes this to the CCC library, and the CCC library then filters all messages whose source is not in the access control list. This very simple level of security is intended primarily to prevent external attacks such as switching media tools transmission on or off, and thus compromising the privacy of users. Note that the X magic-cookie mechanism is not too useful here, as the cookie would have to be carried in over CCC packet, which lays it open to attack from anyone who can capture multicast packets.