Playtest not re-processing nodes and running on latest graph until second entry

[lalalune]

Currently, playtest tests the last state of the graph.

To test: Make a new graph with a hello world. Try playtest, should return nothing. Try playtest again, should return input.

This was probably always a bug, actually, but we didn't notice because process graph was being called on every action. As we are not processing every action, we'll need to call the process graph before playtesting.

[michaelsharpe]

I did set up a process punsub sevent that should process the graph before the run. But there may be some timing issues.