fixed a bug in the draw item method that involved a call to the no longer existing getExplodePercent(section int) method. The int was boxed into an Integer and getExplodedPercent(Comparable key) has been called
enabling selection on charts
introducing data extension
introducing item rendering strategies
removed unecessary variable and method and moved variable declarations to the top of the file
change code to follow more the 1.6 style
 - added add changeListener method to WithChangeListener using generics
typed cursors and selection extensions (datasets are still not typed but should probably be)
refactored changes in chartpanel to 1.6 also replaced overriden getListeners method with the new version from Component
change to the getListeners method in ChartPanel made a test unnecesssary
more 1.6 changes
further 1.6 refactoring with a few exceptions the classes are now typed if necessary
Merge pull request #15 from MichaelZinsmaier/selection_clear_history

Add support for item selection to JFreeChart plots