Added support for socket.io (naive and incomplete implementation)

- Server: libraries moved to lib/ and can be used in client-side
- Server: On adding new record metric watcher sends a socket.io event to all web clients
- Client: LimitedSizeStore is used
- Client: all dependencies added to bower.json

TODO:

- Client: Hardcoded server address.
- Client: Plot full redraw on getting new data.