On-Chain Random Numbers

We are introducing an on-chain RNG based on RANDAO. It may be leveraged by smart contract developers to introduce random numbers into their applications.

The following article explains on-chain randomness functions and how they will be used when POSDAO is implemented. It includes concepts and an example, and is a good place to start.

https://forum.poa.network/t/reliable-randomness-bringing-on-chain-entropy-to-the-xdai-stable-chain/3015

The current implementation requires a chain running Parity's AuRa consensus mechanism with version 2.7.2+. The Random Number generation contract was introduced in this PR.