The start.sh and stop.sh scripts receive a set of arguments from
openvpn when invoked from tunnelUp.sh and tunnelDown.sh. They are:
* $1: network interface for the VPN (e.g. tun0)
* $2: interface MTU (e.g. 1500)
* $3: link MTU (e.g. 1570)
* $4: local IP (e.g. 10.47.10.6)
* $5: remote IP if TUN (e.g. 10.47.10.5), network mask if TAP
* $6: "init" or "restart"
This commit makes these arguments available in
transmission-pre-start.sh, transmission-post-start.sh,
transmission-pre-stop.sh and transmission-post-stop.sh.