Feature: Alternative solution to a pseudo random number generator

I realize newer versions of browsers offer `window.crypto.getRandomValues`. But to build compatibility with all browsers the reputable [Steve Gibson](http://www.grc.com/) security expert created a JavaScript solution to a [Ultra-High Entropy Pseudo-Random Number Generator][1]

Written in pure JS it is very possible to have **ultra-high entropy** random numbers *without* need for built in browser support. He has performed several tests concerning the randomness which he documented on [his page][1].

It is released to the public domain.

[1]: https://www.grc.com/otg/uheprng.htm

- [x] Integrate GRC's UHE PRNG
- [ ] Update generated files
- [ ] Run tests on known browsers
- [ ] Run tests on FireFox / older browsers
- [ ] Verify this is a cryptographically correct PRNG appropriate for PGP