Changes

Fixed transitive closure in loaded graphs.

While nx.transitive_closure_dag(g, o) can be passed a topological ordering o,
this silently produces wrong results if o does not contain all nodes (but
only the references ...)
 (commit: d8595ec)

Remove non-graphviz attributes from graphviz files.

This removes our internal, semantic attributes (which would be
ignored anyway), so the .dot files are much more concise and
readable. It can be turned off using configuration (e.g., for
debugging purposes).
 (commit: ebb032f)