Document local remote network lists in OpenVPN GUI

The local and remote network fields can now have lists of CIDRs, so document this in the GUI.
Document remote network lists in OpenVPN GUI

Also, now the advanced route command is not needed. So change the example to the "remote" command, which can be useful in the advanced box.
Merge pull request #356 from phil-davis/master

Document OpenVPN local and remote network list options