Renamed the 'keyEventEmitter' utility module to 'keyboardEvents'
Changed the #on interface so callbacks are passed in an object, and keyhold events are emitted only if subscribed.
Added the options to change the interval of onkeyhold events and the the context from document to window.
Added the #off method to remove subscriptions to one or more events of a given key.
Changed the way keyboard events are subscribed according to the changes in the KeyboardEvents utility module.
Fixed the link to keyboardEvents.js and set canvas size separately.