change the pipe into a bullet in the lightbox overlay

Changes the "|" (pipe) to a "•" (bullet) in the lightbox overlay.

![no-bullets-in-these-guns-but-my-bear-is-fully-loaded](https://f.cloud.github.com/assets/362783/837820/67728f78-f30f-11e2-9438-269c2be2cc4a.jpg)