Rewrote netstat commands as Popen piped commands

The original version actually failed for me. I am led to believe that all the pipes were being
passed to netstat as it said "I don't understand the option ':'" which came from the cut command.
At the cost of simplicity, this should do what we want properly. Alternatively we could move the
awk/cut/sort into python.
Added remote_host variable to docker conf

In order to whitelist IPs allowed to connect to notebooks, we need to know who the remote target
connecting is. We can blacklist on IP address only, as we have no way of authenticating them. While
we do have access to other information like cookies, we have no SSL nor way to know what
authentication method the galaxy server will be using.