Random sorting

Now you can sort the JawnsController results randomly. To this, simplify specify &seed=something, where you pass in a randomly generated float between -1 and 1. Be sure to only create this seed when the user clicks the "random sorting" checkbox, and then use the same seed for every request in that random sorting session, so that the offset and limit options will work properly without repeating jawns. This seed should be re-generated every time the user decides to start sorting the Jawns randomly.

This parameter also works with ideas and sparks individually. To do this, use `/jawns.json?filter=sparks&seed=whatever`, or the equivalent for ideas. The same thing about saving and re-using the seed value applies here as well.