Added some backend stuff for Continents
Made changes to Jar files, Jars now work with both ControlP5 and UnfoldingMaps

When creating build path, use core-1.5.1.jar instead of core.jar.
ArtistLocationApplet now shows a set of four checkboxes - NOT COMPLETE

This is a rough outline of using checkboxes.  Dynamic filtering needs
to be added, and the checkboxes need to be moved where they are shown
in the visualization.