geth with EVMC

[lrettig]

• EVMC support in geth: EVMC support ethereum/go-ethereum#17050
• EVMC entrypoint alias: Entrypoint alias ipsilon/evmc#36
• evmc_create alias in Hera.

[gballet]

actually, #15 is about using github.com/go-interpreter/wagon

[lrettig]

@gballet one of the tasks in #15 is "integrate wagon into geth" so I renamed it to a generic "geth support" issue. EVM-C integration would be required for that. We can break it out into more issues if you prefer.

[chfast]

This is done.