Options support onClose and onSet 

This allows an options object to also provide `onClose` and `onSet` event callbacks. Previously the directive would overwrite these specific callbacks with it's own required functionality. Now the picker will call the user provided `onClose` and `onSet` (if specified) and then execute it's normal `onClose` and `onSet` logic.

Included some brief documentation on how to provide options and bumped the version to `1.0.3`