Basic module for net instrumentation

This module aims at recording network events and relate them to user-space
processes. It includes the following instrumentation.

 * records connect and accept to match client and server socks objects
 * records sock create, clone and delete
 * records hints about TCP packets sent and received

Instrumentation is performed with kprobe, by overriding the netfamilly IPV4 and
by means of netfilter hooks.