add docs for widget
Merge pull request #4 from mojotech/sjs/docs

add docs for widget
Re-compile using coffescript 1.7.
Make dynamically defined getters and setters enumerable.
Pass all options to Process onto spawned process.
[breaking] Allow non-node Processes.
Make Object.includes successfully copy getters and setters.
Provide a convenient point for JS apps to extend Widgets.
Raise error on failed action in flow.
Clear text input fields before sending keys to fill them.
[bugfix] Set a default timeout of 5 seconds (instead of infinite).
Only retry Then steps.