'net' module: tests and fixes

So far this updates #308 with a very basic test suite, and fixes IPv4 and/or IPv6 address detection.
ttt got removed since all the changes that it had were merged into tinytap. t.pass/fail [calls assert](https://github.com/tcr/tinytap/blob/master/src/tester.js#L64)... which could be why its not showing up as tap tests since those only count the `console.logs`. I count 8 occurrences of `t.pass` which would make sense if tap isn't counting those.

106 could be the event firing. I only get failures 20% of the time.