queryd is added as a new daemon which handles configuration queries over
LUXI. This functionality was removed from confd, which now only queries
over the network.

The queryd user is added to the master group such that it can access
server.pem. The confd user no longer needs to be in the master group.
This fixes issue 292.

Signed-off-by: Thomas Thrainer <thomasth@google.com>
Reviewed-by: Helga Velroyen <helgav@google.com>