event *_base classes should all be abstract

This should prevent us accidentally instantiating one and getting into
exceptionception.
Add my details to the copyright notice

I did a significant portion of this work on my own steam; I've earned
the recognition.
A bunch of changes

-> generify single column with action table generation
-> implement activity status management interface
-> implement events/logging for activity statuses
-> remove extraneous use of url_generator from renderer
-> assorted documentation fixes in renderer

Fixes #16
Fixes #18