nbd: convert qemu-nbd server to use I/O channels for connection setup This converts the qemu-nbd server to use the QIOChannelSocket class for initial listener socket setup and accepting of client connections. Actual I/O is still being performed against the socket file descriptor using the POSIX socket APIs. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1455129674-17255-5-git-send-email-berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>