- Changed references to the two renamed classes (Player -> User and World ->   Environment).
- Changed references to the two renamed classes (Player -> User and World ->
  Environment).

- Moved the event handler from the base event class to here, as it seemed more
  sane to put it in the file which will typically be required instead of one of
  its dependencies.

--HG--
extra : convert_revision : svn%3A39a105f4-52d6-0310-bb1b-d6517044f2e4/trunk%40149

ged/mues