#15 Backtrack on operations

[Jesse Yanutola]

It seems that the user should be able to backtrack on some of the operations when a mistake is make, sort of like a mini-undo feature. It has been my experience using programs that the Esc key is generally used for this. For example, there were times when I accidentally clicked the New Root button, or forgot to double-click to end the root drawing while I was creating a new root. For example, if I click New Root, and then change my mind, I should be able to press the Esc key to cancel that operation. Furthermore, if I'm drawing a root, and I forget to double-click to end it, it makes sense that I should be able to press escape to cancel that last line segment. This concept could be utilized in other aspects of the program as well.