+ refactorings, renamed monitor-app.js to monitor to allow dependency as:

require('/cluster2/monitor')
   .monApp
   .debugMiddleware
   …

etc.
~ bugfix & refactorings of cache-mgr.js
Update README.md
Update README.md

api draft
+ refactorings to alter the order of watch callback for 'null' key, which aligns with the watch callback for non null
Merge remote-tracking branch 'origin/cluster3' into cluster3
+ refactorings and simplifications
- useCache from master & worker
- '.js' dependencies from all references
- Cluster class, using #listen, and plan to support #run as 2 functions
- Cluster as emitter instance, use require('cluster2/emitter') directly, if overwritten with your own emitter, then that should be what u want to register handlers to.
~ adding 'isMaster', 'isWorker' api to give same api for 'cluster'
~ 'workers' isn't provided because cluster2 doesn't know the workers, only the created master knows.
Merge pull request #25 from inexplicable/cluster3

Cluster3