Improve Isotope rendering

[stevepiercy]

See http://webdesign.tutsplus.com/tutorials/quick-tip-how-to-use-html5-picture-for-responsive-images--cms-21015

We will need to create various sizes of all the images used on:
https://trypyramid.com/community-powered-by-pyramid.html

[stevepiercy]

Just saw this come through my Twitter feed as a possible solution:
https://www.npmjs.com/package/resize-image-loader

[blaflamme]

looks interesting