Auto-play lightbox

[chrismelbourne]

Thank you so much for the lightbox - it is beautifully done and a major feature that adds so much value to image-gallery!

Just a little feature request:

1. Add an parameter option (e.g. autoplay: true) to play through the lightbox starting from the clicked image and cycling through everything.
2. This play slideshow may be paused and unpaused by say clicking the spacebar.

This sort of emulates the experience of Adobe Bridge, when we press ⌘L to start a slideshow, it will auto-play, and pressing spacebar toggles pausing. {escape} returns to the gallery.