Bug in non-blocking TCP connect fixed

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>
Shutdown stress test enabled for IPC

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>
Improved error reporting in nn_usock_recv

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>
Initial implementation of nn_device added

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>