Assign min and max ranks to subgraphs
Keep subgraphs vertically tight in ranking phase
Save the starts of dummy chains
Properly parent nodes in a dummy chain
Don't enable timing instrumentation by default
Make rankdir and align case-insensitive
Transform subgraph dimensions based on rankdir
Add code to build layer graphs in order phase
Some reorganization to order phase to prep for compound ordering
Sort by subgraph across layers

Still need to prevent subgraphs from getting intertwined across layers.
Add function to resolve barycenter conflicts
Add index to result from resolve conflicts
Work on sorting entries from resolve conflicts
Fix to sort when there are no barycenters
Hook in processing of constraint graph
Add function to update subgraph constraints
Treat cluster to cluster edges as lighter than cluster to node
Add new implementation for add border segments
Rework parent dummy chains to support an arbitrary LCA
Detect type-2 conflicts invovling a border segment