debug mode

two ideas...

1) why not have SwingEngine.DEBUG_MODE be mutable.
2) what about modifying it so that instead of it writing to system out 
you give it a listener for logging. By default there would be a simple 
listener that just went to System.out but users could optionally write  
a listener that would shunt the output to Log4J or whatever their 
favorite logging package was.

my only question on 2 is if it should support multiple listeners or 
just one.


I think it cold work as follows... if in debug mode it ships it off to 
a class that passes it off to the listeners. If there aren't any 
listeners registered the first time it would add in the default one.



-Kate