If you're attached to RegExps, you might be able to just use `'\b' + tclass + '\b'` when constructing so it matches word boundaries.

The other thing we should do is actually set up listeners instead of hijacking `window.onload`. We do this in our transform script so we should do that: https://github.com/facebook/react/blob/master/vendor/browser-transforms.js#L106-L110