Our users are often confused by the output from programs such as zip2john sometimes being very large (multi-gigabyte). Maybe we should identify and enhance these programs to output a message to stderr to explain to users that it's normal for the output to be very large - maybe always or maybe only when the output size is above a threshold (e.g., 1 million bytes?)

I found two issues with breakpoints while playing around with timertool for #80.

1. Changing a breakpoint does not have an affect on a running program until it is paused and then restarted. Breakpoints are passed to the simulator thread as function arguments (which is definitely necessary), but that means changes to the UI do not affect the simulator until the threads is shut down and restarted.