Population Diagram Styling: overdrawing when there's a branch

[stappan]

All vias are aligned in a single vertical, even when there is branching, making it a) a much longer diagram than necessary, and b) making it seem like the modeling is wrong.

request: separate different branched paths into separate "columns" to make it easier to review.
see screenshot for https://composer.scicrunch.io/statement/24

[stappan]

This may be happening when the initial (first) destination is an afferent terminal. if the first destination in the list is an axon terminal, it might be behaving properly.