Update statement generation

It should generate statements that can be displayed like this:
![statement](https://cloud.githubusercontent.com/assets/1731223/5044294/c63c2cd2-6bf7-11e4-9b84-8f98883fe53b.png)




Right, thanks. We'll need to pass in both `account.id` and `account.account_number` then (so we can use the user api). Not ideal :/   I guess we could just pass in the account number and lookup accounts from it, but `account_number` probably isn't indexed the same as the id, so it'd be slower. Thoughts?