some custom event to communicate a value to listeners. This is for that.
CommandEvents are close, but are all dispatched using a single 'type' value,
so a single handler must have a switch statement in it (unless you're
a controller, which has magic to call the right method.)
git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@4606 542714f4-19e9-0310-aa3c-eee0fc999fb1
Ray Greenwell