Events are now subclassed like actions
Events are now subclassed like actions

Instead of making one event class for all events, subclass them. This
 removes any need for setting a category. Only key events and collision
 events need special cases. As with actions, the right class for a
 particular action can be instantiated by requesting a search through
 the base class's registry with a class method.
Also renamed the exception handler class name.

rlc2/pygame_maker,rlc2/pygame_maker