Could benefit from some minor modifications to
python client backend and tray app:
* Client backend and ovpn3 both implement connection timeout.
Client backend should defer to the ovpn3 implementation.
* Client backend and ovpn3 both implement DNS server config
and SystemConfiguration event sent to
'Setup:/Network/Global/IPv4' for 'VPN up'.
Client backend should defer to the ovpn3 implementation.
* Ensure that system state changes (sleep, wakeup, network
roam, fast user switching, etc.) don't cause conflicts
between client backend and ovpn3 core both trying to
implement similar functionality.
* Tray app should render error detail in >FATAL: messages.
Right now tray raises a Disconnected notification but
loses any error detail.
