Changes

* Where are the magic numbers in the code documented?

* Where are the magic numbers in the code documented?

* Is the file format for TA documented somewhere, so that we can write a Logo to TA translator?

* Is the file format for TA documented somewhere, so that we can write a Logo to TA translator? (this would require some complicated logic, the resulting block stack would have to fit on the canvas and not overlap itself too much, I have found laying out blocks a difficult task if wanting to keep a complicated program readable. Unfortunately, the canvas does not scroll - tony)