Sort cmesh so it maps like a mesh

The general idea here is that I want to map networks that aren't just
meshes to the placement tool used by the mesh network.  The other
network types that are supported are easy: mesh just maps directly and
it doesn't matter for a crossbar.  This makes cmesh map pretty well.
Record (x,y) position for all nodes

This allows me to use some of the code that's been designed for chips
that can be laid out on a grid to map to chips that can't be laid out
on a grid.  It's a bit of a hack, but for now it'll have to go in...