i think im done exit command. i may need to gracefully exit once i have shapes and stuff to work with. the invokers work by passing in the drawpanel into the actionlistener constructor and then executing the command created in the constructor within the action performed. passing in the drawpanel should let me be able to modify the contents of it once shapes are added in
merge latest master into command implementations branch
got undo to work with shapes, havent tried it with other stuff
got redo to work but only upto one time
commit before experimenting on redo multiple times
 redo/undo of drawing shapes works i think. exit command works too but doesnt need a redo/undo for it
Merge pull request #12 from nbguzman/commandImplementations

Exit and Draw Command