Further improvements to the features

The features still have something to desire.
The same code is repeated in most of the features, which seems unnecessary and complicates the code - hides what you really want the feature to do in a pile of goo.
One way to improve this would be to make the features extend a base class - but i don't like doing extends and think that it is bad coding practice, so will seek other alternatives.

Maybe, to keep in line with the already present feature registrations, a class could be made that does all the boring stuff and features can register if they want that functionality aswell.
Stuff like on private message for controlling the feature.

Also, to stop the 4 line if condition at the start of onMessage, perhaps a proxy could be used?

Anyway... thats all implementation details that aren't important (and are just so I remember them really) - the important thing is simplifying it as much as possible.

Correct, understandable code ftw!