Repaired export-dependency-graph property and dropped unsupported export-to-yaml property

[cmnrd]

Fixes #2434

[erlingrj]

Great that you could handle this. Looks like export_dependency_graph is now called only after the program has completed? So you need to do Ctrl-C, or have timeout, or some other way of terminating the program before you get the graph?

[cmnrd]

Yes, that is how it currently is and I think its good enough for now. Ideally, we would call the export before the execution starts, but currently the assembly of the port connections is tied in with the execute function. Separating it out is possible, but requires some more work.