[GREENFOOT-37] Need functionality to halt programs
If one of the greenfootobjects/actors have a loop that never terminates, it should be possible to interrupt it. We probably don't need a new button since it can be integrated with the "pause" button. --- When hitting the pause button, we shoudl check if it actually pauses the simulation within a certain amount of time. If it doesn't the button should change to a STOP button that terminates the execution.
- Issue type: Bug
- Priority: Medium
- Fix versions: 2.0