Refactor long array() syntax to short []

Since app is using PHP 5.4+ already, the longer `array()` syntax can be
refactored to shorter `[]`.

Use https for Flickr (web bug #67227)

See also http://code.flickr.net/2014/04/30/flickr-
api-going-ssl-only-on-june-27th-2014/

Added script to fetch elephpant images from Flickr.
Modified 'update-backend' to invoke the new script.