Update documentation, TODO.
Add a "test" to verify that event_definition.h can be used standalone; fix it so it can be used standalone.
Check in part of Obliterate_Event unit test; update documentation.
Remove some apparently-unneeded complicated functionality from the event system.
More notes for obliterate testing.
Reimplement event-active obliterate lockout; this method is efficient and easy to describe (and not buggy), but more loosely bounded. Attempt to improve bounds later, perhaps?