Integration with fork of paritytech/polkadot

The core-primitives re-write has been integrated into Polkadot in our experimental branch. It allowed us to verify that compilation works, and that the node runs properly. We note that the integration we performed adds our changes directly to the polkadot repository, and is not yet using the C++ 'crates' in mayon. However, in order to keep the fork light (the Polkadot repository is already quite large), we will be using the separate mayon repository in the short future.