Echo JS 0.11.0

You're welcome. Sample implementation outside of react-forms: 

- https://github.com/n1k0/kept/blob/master/src/js/mixins/UndoStack.js
- https://github.com/n1k0/kept/blob/master/src/js/components/KeptApp.jsx#L14-L29

No need of Om, Mori or immutable data structures really http://prometheusresearch.github.io/react-forms/examples/undo.html