Listenable

addListener( callback ) → {callable}

Adds a listener to the current object.

Name	Type	Description
`callback`	callable	callback for when the event occurs

removeListener( callback )

Removes a listener from the current object.

Name	Type	Description
`callback`	callable	callback that was originally registered

alertListeners( )

Alerts the listeners that an event occurred. Data passed is optional

Name	Type	Attributes	Description
`..data`	*	<optional>	Any data desired to be passed to listeners

new Listenable()