nn_timeout renamed to nn_timerset

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

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

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>
Worker thread is executed as part of the library context.

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