Galleries

Way way overdue, this replaces the galleries with the lightbox version.

![gallery](https://f.cloud.github.com/assets/518943/1382288/8ca980c0-3b2c-11e3-80a8-abd0b6069af2.png)
![desktop-galleries](https://f.cloud.github.com/assets/518943/1381837/4b5a9fd8-3b26-11e3-9c7c-842a26955b8d.png)

- Initial support for hires images
- Adds ESC key support for exiting
- Adding Launch CTA
- Fix back CTA when swipe is on
- Reduce vertical scroll when possible
- Swipe interaction disables slideshow
- Better HistoryAPI support
- Non-JS/SwitchOff version gets the previous style
- Support for image ratios of 5:3, 3:2, 2:3, 1:1, 1:2, 16:9, 51:50, 321:123, (x+y)/5:2πr
- Make best attempt to fit images to screen size (landscape in portrait view, portraits in landscape, squares in landscape, circles into triangles, hexagons into rhombi, etc etc)

![lazycat](https://f.cloud.github.com/assets/518943/1381830/3adcf570-3b26-11e3-92b6-8f4a1ae19124.gif)