Upgrade socketwatcher dependency.

0.2.0 fixes backwards compatibility with node < 0.9.9.
See github issue btrask/node-socketwatcher#2 for details.
Merge pull request #65 from nearbuy/upgrade_socket_watcher

Upgrade socketwatcher dependency.
Merge branch 'develop'
Add support for multiple pcap sessions.

As the comments suggested, pull out per-session code into a class
that gets instatiated each time you createSession. This way a
single process can have multiple captures going at once.
Add a multi-interface example.
v1.0.0 - Pcap is out of beta.
* Adding libpcap version which is required