very very skeleton Commands and Invokers. Commands will handle execution, undoing, redoing while Invokers will create and call the commands. DrawPanel acts as a receiver that knows how to perform the operations. UI items will act as invokers (classes implemented actionlisteners so that a click on a tool will determine what to do).
Merge pull request #6 from nbguzman/commandSkeleton

Skeleton structure of Commands and Invokers
fixed up a few small things in the code
Merge pull request #7 from andeic/compositeSkeletonUpdate

fixed up a few small things in the code