.openvpn: Add OpenVPN settings
.openvpn: Make OpenVPN clients send ping packets
.openvpn: Change the names of the log files
.openvpn: Redirect all traffic through the VPN
.openvpn: Enable IP forwarding and create NAT rules for the VPN traffic
.openvpn: Merge multiple up scripts into one
.openvpn: Use custom DNS servers on the VPN clients when connected
.openvpn: Apply DNS servers pushed by the VPN server
.openvpn: Port the up and down scripts to Windows
.openvpn: Use single quotes instead of double quotes
.openvpn: Remain privileged not to interfere with finalization process

After being unprivileged, commands like "route" do not work, which makes
it impossible to release the resources. On Windows, chrooting also leads
to improper initialization.
.openvpn: Use shorter options
.openvpn: Clean up the settings
.openvpn: Allow the server to change its IP address and/or port number
.openvpn: Add missing options that are not yet used