Custom JList class for the LayerList

Did this to allow for us to add a flag to the CurrentLayer. This will
also allow the user to manually select the CurrentLayer. Right now I
can't get the user selection to work although if you right click on a
JList element a drop down menu does appear. Could use some help figuring
out why the actionListener doesn't seem to work for selecting that menu
option. For now it properly flags the Current Layer for all the cases of
changing the Current Layer that we had before, by changing the text to
Red. This can be changed to whatever effect we like best.