Scale initial images in galleries

The gallery list view has low fi images that are much smaller than their upgraded counterparts. We can scale the initial images to reduce the pop-in effect of upgrading. Portraits use a responsive-ratio-like style to take a height according to the width. Landscapes initially style with 100% width.

![screen shot 2014-09-16 at 13 02 10](https://cloud.githubusercontent.com/assets/4549425/4286850/096990e8-3d9b-11e4-8034-16e794a8d823.png)