Monero Cryptonight variants, and add one for v7

[moneromooo]

See https://github.com/monero-project/monero-site/pull/599 (not published yet)

Note: I've not tested that as I don't have a setup for this, but it's sooo simple :)

Needs the multihashing patch in https://github.com/zone117x/node-multi-hashing/pull/49

[Snipa22]

This would brick the pool at this time if pulled in. So not accepting until I have surrounding patches done and ready for this, and that won't happen until the monero community decides if we're okay with this patch/PoW change.

[LegolasGChief]

Any ideas what changes will need to be made for Aeon?