Fix windows netstat usage

[baumatron]

Hopefully fixes #3

netstat should get the -n parameter so it doesn't try to come up with a human readable name for ip addresses, which can take a long time and isn't needed.

The regex to match processes with the provided port should match only the first column of output from netstat because we only care about local ports and definitely don't won't to kill processes connected to a remote port that happens to be the port we provided.

This also adds the /F flag to taskkill which seemed needed to kill the process I tested with.

[faboweb]

Ping!

[zdroyer]

I just wanted to create a PR with this modification. On a windows machine 'netstat -ao' lists ALL the listening ports so without the '-n' switch it can take several seconds (my case), depending on the single hostname lookup time.

Similarly, lsof on Unix should be also called with -n switch, but it's less painful because only one port will be listed, but still it '-n' would make it faster.

[baumatron]

@tiaanduplessis