Use pubsub to decouple parents from children

- Use a pubsub system to subscribe and publish update event from children to root.
- No longer use path class, each wrapper instead stores the whole path array
Merge pull request #10 from mquan/use-pub-sub

Use pubsub to decouple parents from children
Add bower.json
Fix bower.json
Fix bower.json error
Update bower instruction
Merge branch 'master' of https://github.com/mquan/cortex

Conflicts:
	src/cortex.js