Add Random Number Generation

[randomPoison]

Add a library for lightweight random number generation. The focus should be on low performance cost and ease of use. Crypographic soundness isn't important, though the RNGshould be fairly robust in terms of not being obviously biased to a human observer.

Note that this is only meant to be a first pass, the solution doesn't have to be particularly robust. Future usage and iteration will serve to flesh it out more.