Event emitter component.
$ component install component/emitter
Emitter may also be used as a mixin. For example
a "plain" object may become an emitter, or you may
extend an existing prototype.
var Emitter = ;var emitter = ;emitter;
As a mixin:
var Emitter = ;var user = name: 'tobi' ;;user;
As a prototype mixin:
var Emitter = ;;
Register a single-shot
removed immediately after it is invoked the
fnto remove a listener.
eventto remove all listeners on that event.
event with variable option args.
Return an array of callbacks, or an empty array.
Check if this emitter has