Put modules in JScrollPanes so they can scroll if
resized. Also packed them when first created to ensure
they size correctly.
Fixed an issue with cascading frames. Also made it so
you can hide frames by clicking close, and bring them
back using the "Window" menu. Still having a weird
issue with JInternalFrame not drawing it's border
correctly when it gains focus through the "Window"
menu. If anyone else wants to take a crack at it, feel
free. The code is in MDIFrame.java