Use only a single TCP option

[yaplej]

Originally OpenNOP was using TCP options 30 & 31 for injecting data into the TCP stream so two OpenNOP system could detect each other. Now I have implemented Network Optimizer Detection ie (NOD) everything should be done using this single TCP option.

Option 31 is still being used in compression.c and worker.c for detection compressed TCP payload. This should be moved into the NOD option as an additional piece of data attached after the main NOD header.

So far this is only being used to flag that the packet is:
0 = uncompressed
1 = compressed
2 = deduplicated