Lightbox gallery fixes

- Alt tag for trails was pulling in caption 
- Preserve back button functionality
- Fixes integration tests
- Another attempt at sizing the thumbs to work in more situations (1:1 ratio now)

![lg-thumbs](https://f.cloud.github.com/assets/518943/768175/894e1962-e899-11e2-9de7-301521fa1207.png)