Added FSM assertions to the transport utils

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>
FSM asserts added to Windows version of nn_usock

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>
FSM asserts added to nn_ep

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>
FSM asserts added to protocol implementatins

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>
FSM asserts added nn_timer

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