A small app hacked together in JS to select a random constraint for a
CodeRetreat. Just hit Enter or click anywhere to get a different random
constraint selected in a couple of seconds. Edit constraints.js to change the
possible options. Seems to work in Chromium 28 and Firefox 24.
Read more about CodeRetreats at http://coderetreat.org/
Online version: http://attilammagyar.github.io/cr-constraint-selector/