Add binding for pcap Send

Updates completed as per your comments on the previous pull request.
I also changed the example to match the change to ThrowException in the send method.

FWIW, my issue with >60 second spool up was in pcap_findalldevs. My system was hanging when iterating through the USB driver for interfaces!  Nothing to do with our code. tcpdump was showing the same behaviour when no interface was specified.