[engine] smart contracts

[florianlenz]

Feature / Issue

Currently we are missing the functionality to interact with smart contracts. Since ether.js took years (ok, minutes - but still way too much) to load in the otto vm we couldn't deliver smart contracts. However, we need smart contracts in the VM asap. There are two options:

1. We build a wrapper around geth smart contracts
2. We switch the vm ([engine] new JS VM #81) and get ether.js running.

Switching the VM is probably a better idea since otto vm doesn't provide a few features that we need (e.g. sandboxing)

Acceptance criteria

• interact with smart contract (read, write)

Depends on:

• [engine] new JS VM #81

[borjantrajanoski]

@kevowevo this will be done at the 28th