Planned Undo

Planned what to do for Undo feature, started implementing it. Not done
reconnecting to github
Partial Undo feature

Can undo creating and deleting objects. Next step, undo moving objects.
Almost got undo movement

Can undo a note movement. One problem when starting to undo a chain of
actions. It will first undo the current change, which should be in the
same position, but it causes the note to shift down a bit. Then it will
start going backwards and move to the previous position.
Fixing Undo & Starting Redo

Trying to fix the problem when undoing a move object. Started creating
the arrays for redo feature.
Fixed Undo, should work

Fixed the problem with undo feature. Print statements for debugging are
still in code. Need to fix code because some of it was copy-paste a few
times so variable names are a bit confusing.
Clean Undo, start Redo

Undo code has been cleaned up a bit. Still need to implement undo
rotate and pinch. Started to redo bring an object back.
Merge pull request #17 from nang1/Nicole

Adding Partial Undo feature