TODO

* calculate each photo's size dynamically using its dimensions vs viewport size (and probably recalculate on window resize/rotate)
* thumbnail size depends on browser window size
* separate sitemap page with text links (visible to users if they want)
* About page
* JCache API instead of a Map
* image sitemap using sitemapindex: http://www.sitemaps.org/protocol.html#index
* images from other domains, how to register a CDN?
* schema.org ImageObject: https://schema.org/ImageGallery and http://schema.org/ImageObject: https://search.google.com/structured-data/testing-tool/u/0/
* Twitter card tags?
* Page per each image
* Keywords from google vision
* Use appengine provided location headers to display user on the map
* Hide google maps for those galleries, where there are no tagged albums

* Mobile: reload google maps on orientation change
* Allow pinch to zoom (doesn't work in fullscreen on Android by default)
* Fix initial photo hash - it should pushState correctly