Custom renderer for lightbox

![1406548510](https://cloud.githubusercontent.com/assets/708296/3720045/28ae7906-164e-11e4-8842-e483b702d34e.png)

Related Waldorf PR (to make sure we don't bork interests): https://github.com/lonelyplanet/waldorf/pull/1365
It might, but the responsibility for handling the response should be down to the app now in my opinion (see the related waldorf pr here: https://github.com/lonelyplanet/waldorf/pull/1365). Especially since the decision for how the content is returned is decided by the app.