Seedable pseudorandom number generator

Usage

var random = require('seedable-random');

random.seed(123);
console.log(random());

As a Math.random replacement

Math.random = require('seedable-random');
Math.random.seed(12345);

- Works as a drop-in for Math.random

- Relatively fast (about 2.5 times slower than Math.random on my machine)

- Seeds itself from the clock by default

- Tries to be pretty random

- Well tested (TODO come up with some PRNG torture tests)

TODO

Possibility to switch the generator (linear-feedback shift register, Mersenne
twister, digits of Math.sin(), etc. based on your needs)

A word of warning

Current implementation just calls Math.sin() with the seed. It's likely that
it's not quite that random (for example, the distribution could be biased
towards numbers near 1.0). Some more tests are needed.