Fixed warning about directly calling a component.

  React 0.12 depreciated directly invoking components, they now need to be wrapped in a React.createFactory call. We now do this for the handlers passed in to the router in order to suppress the warning.
I think this could be:
```
React.isValidaElement(this.route.props.handler) ?
  React.addons.cloneWithProps(this.route.props.handler, props) :
  React.createElement(this.route.props.handler, props);
```