Add eventric.js

Modern web development of complex applications tries to achieve several goals - some more recent examples are:

* Focus on the behavior of users and go from there (Behavior-driven development)
* Avoid architecture that might have side-effects, emphasize being reactive ([Flux](http://facebook.github.io/react/docs/flux-overview.html), [CQRS](http://cqrs.info/))
* Have an ubiquitous language throughout the project (from naming methods to naming css classes, Domain-driven Design)

[eventric.js](https://github.com/efacilitation/eventric/) enables developers to reach this goals more easily