Pass store as prop to Root component in real-world example

[ForbesLindesay]

The advantage of passing the store in from the top level is essentially the same as the advantage of passing the History object in from the top level:

It makes it easier to re-use the Root component in a universal app.

[gaearon]

Unfortunately this breaks hot reloading reducers until we fix the underlying problem. #301 #350

[gaearon]

This is superseded by #667, where I removed <Root>.
Thanks!