Updated Gui Interfaces

I have updated the interfaces- especially for the GUI- in fact I pretty much deleted the old ones.
Some of the ones under common  classes will likely still need more work too.
My thinking is that many of the other classes will build or return a concrete class that implements DataTable, or some other common class that makes sense for the data type.

The main GUI class- especially for any sort of record view- is likely to be some sort of table structure similar to the C# GridView. I have set up some preliminary (possibly permanent) abstract classes that go with this idea. Concrete classes that extend BoxedTable can be created directly using a class implementing DataTable.

Anyway, I hope I am making sense. This many layers of interfaces, etc is quite new to me.

One other Note:
Since GUI's in Java are new to me, I did create a small number of experimental concrete classes to confirm the layout of the interfaces will work. I have placed these classes in a package called "playground." They are not intended to part of the final project, and do not have test classes.