#445 Fix and improve QNX support

[Pablo Romero Cumbreras]

As far as I have checked there is some prototype support for QNX. However, when testing on QNX v7.1, I found some roadblocks preventing me from an off-the-shelf build and deploying to the RTOS.

After a few tweaks in the code, I could build the project and run the examples without any issue, verifying the expected behavior with WireShark.

[Armin-Hagen Weiss]

Hi Pablo, would be good if You could attach the diff to include Your changes in the code.

[Pablo Romero Cumbreras]

[Armin-Hagen Weiss]

Changes taken over from diff except last change in vos_thread.c (code has changed) and vos_sockTSN (code has changed). IEEE802.1Qbv support, here called TSN support, was implemented only for testing applicability and so vos_sockTSN.c will be most probably removed.