* Some hacks for graph visualization

* More betterer

* Remove debug prints

* Cheap temporary hack to deal with zombie users issue

* Less hacky fix for the zombie users issue

* Change to use get_name instead of get_friendly_name; misc. cleanup of dot output

* Allow '.dot' as VisualizeTree output format, and make it default

* Cleanup, and some documentation of this jump distance nonsense

* Comment edits

* Another comment edit

* Fix typo

* Remove reverse_topological_sort function (it's not needed)