Simplify the way applications can get notifications when an effect finishes.
Now, instead of the 'DistortedEffects.(de)registerForNotifications()' 2 APIs, we call a single 'Effect.notifyWhenFinished()'.
Correct the Legal notice.
Rename all the classes that are not exported to application to 'Internal'
Progress with support for Effect classes.
Some progress with Effect classes.
Big mess - nothing compiles now; classes moved around.
Fix Lint warnings, correct a lot of comments, adjust EffectListener interface.
Cleanup, consistent variable names, minor details.
Major: the MessageSender thread used to be running all the time in a tight loop!!
1. new package 'message'2. Rename the 'Grid' classes to match