Implement L7 Spy application

[aperezdc]

Implement the L7 Spy SnS application as specified in the design. In particular, ensure that the following is implemented:

• [ ] Integrate nDPI timing with the SnS loop.
• [ ] Flow state objects.
• [ ] Shared detection state objects.
• [ ] Flow identification.
• [ ] Application/protocol detection.
• [ ] Attaching metadata to packets.
• [ ] Transparently forwarding packets.

[aperezdc]

This has now been merged in the swall-starfruit branch.