I think I'm least likely to break something if I do this as explicitly
as possible rather than trying to figure out the right helper to put it
in once and for all. So just add some boilerplate to reset all state at
the start of each onpress1 handler. This seems like a good choice since
we aren't planning to add a lot more menus that would quadratically
explode the boilerplate.
Now I only assume 'run' and 'stop' are always visible.
And there's no point wasting space on the 'code' text in that case.
I've also standardized the boilerplate on all the other buttons.