The IPC pipes are now file objects, not file descriptors:
* mandos (ClientDBus.CheckedOK): Reorder to group methods, signals and
properties together.
(ClientHandler.handle,
ForkingMixInWithPipes.process_request,
ForkingMixInWithPipes.add_pipe_fds,
MandosServer.add_pipe_fds): IPC pipes are now file objects, not FDs.
(MandosServer.handle_ipc): - '' - Take additional argument "sender"
containing the client IPC file object;
all callers changed.