Enable compilation of contracts without source

[Shirikatsu]

Currently contract compilation works by supplying Solidity source code. This creates a contract instance that enables direct interaction with the contract functions.

We should be able to create contract instances without source code.

What other things would be necessary to facilitate this?

1. compiled bytecode
2. abi

We require bytecode in order to actually build the contract instance.

We require abi in order to correctly decode the structure of the bytecode into named functions for interaction.