Analyse incoming transactions using Hephaestus

[RafaelAPB]

Given a built model we now should be able to analyse incoming transactions. The starting point is a cross-chain model and a (blank) cross-chain state.

Requirements:

1. For each new incoming or outgoing transaction, before it is sent ( receiving receipt from counterparty gateway or creating a transaction): simulate the update the cross-chain state.
2. If simulated result from execution is valid: 1) if receiving transaction, update the cross-chain state; 2) if sending the transaction, send the transaction and upon completion, update cross-chain state
3. If simulated result from execution is not valid, see next issue

[brunoffmateus]

I will do this task.