Exercises

1. Update Drawing so that it resets the turtle position when the user clears the screen with the Reset button.
2. Our tests have a lot of duplication due to the repeated calls to triggerRequestAnimationFrame. Simplify how this is called by creating a wrapper function called triggerAnimationSequence that takes an array of frame times and calls triggerRequestAnimationFrame for each of those times.
3. Loading an existing script (for example, on startup) will take a long time to animate all instructions, and so will pasting in code snippets. Add a Skip animation button that can be used to skip all the queued animations.
4. Ensure that the Undo button works correctly when animations are in progress.