This commit add the support of netmap as a capture module for haka.
There is some documentation to compile and configure netmap and then start haka
using netmap module.
Implementation try to follow haka coding style.

This is a Proof of concept and several things have to do to have a fully
functionnal and stable module:
- architecture have to be modified to avoid packet copy
- only ipv4 packets can be filtered
- code must be more modular
- improve trace
- add statistics mechanisms for netmap
- clean code and verify memory leak or corruption