WIP: Bug/paypro

 * Refactors PayPro, model and controller (remove duplicate code, add peer payment fetching, new tests)
 * Refactors Addressbook (remove signing)
 * Refactor send and sign functions in Wallet
 * Removes networking in 1-1 wallets.
nit: let's add a `log.warn('PayPro: more than one output received')`