This tests the RFC3706 DPD implementation, with dpdaction=restart on east,
and dpdaction=hold on west.

West will trap, while east will attempt to restart the connection when
DPD times out.

Order of Operations:

1) East sets up for tunnel
2) West initiates tunnel to east
3) We idle for 20 seconds, to prove that DPD R_U_THERE/R_U_THERE_ACKs work.
4) West blocks traffic on eth0
5) Both sides trigger a DPD Timeout:
	East attempts to restart/reinitiate
	West puts the eroute into %trap
6) West removes the traffic block
7) West will receive the packets from east, and should renegotiate the tunnel

