Add Argon Protocol Testnet

[blakebyrnes]

This PR adds the Argon protocol to the test networks.

I couldn't tell from some of the recent PRs if you want the build files to include changes or you'd rather have those omitted. Let me know if you want me to remove them.

I also am unclear what process we need to show for basic background/verification that the chain is legitimate. Please advise on anything you need there as well.