1. A trivial change in GeniCM; only look at the first two interfaces in the
   link if it references an external node. We already depend on the fact
   that the first two interfaces are in the same order as the two stitch
   points in the stitching section, so as long as we ignore external nodes
   after the second interface, setting up the virtual state for a lan works
   just peachy.

2. libvtop_test: a bit less trivial, mostly cause of vlan tag pre
   reservation when stitching. When we encapsulate a lan we build another
   lans table entry that is linked. There is no need to do this when the
   encapsulation is vlan, and in fact I had changed links a long time ago
   to not do this, for the exact same reason. Lans are little bit more
   complicated but I think I got it.