Fix route transition hooks not firing when used without JSX

Since React 0.12 components should be wrapped with `React.createFactory(...)` when used without JSX. This factory method does not carry over static properties which breaks `willTransitionFrom` and `willTransitionTo`. I have provided an example of this in a separate branch, see 0b447d6.

The factory does however expose the wrapped class in its "type"-property where we can access the static properties.

Please review!