This emulates two clients behind the same NAT.

road imports north's identity as well. It establishes road
using certificates. then kills pluto hard and established
north. This fails on east with:

"road-eastnet-ikev2"[1] 192.1.2.254 #3: Signature check (on C=ca, ST=Ontario, O=Libreswan, OU=Test Department, CN=road.testing.libreswan.org, E=testing@libreswan.org) failed (wrong key?); tried *AwEAAdrh2

Paul: this seems fixed, but of course the way the test is setup, it will
cause an eroute already in use since both road and north would get the
same src/dst subnets. 
