Support for stitch to Lan:
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.