Arbitrary Denomination Payments

[gakonst]

Debit Spec: https://hackmd.io/6DVYwXtQSM6LEub2LCq9Kg?edit
Cashflow Spec: https://hackmd.io/DgzmJIRjSzCYvl4lUjZXNQ?view
Ben's thoughts on cashflow https://ethresear.ch/t/plasma-cash-was-a-transaction-format/4261
Old Debit impl: #115

Firstly need to evaluate which approach is simpler to implement. Debit is probably easier but has limts in features, however it may be worth it if it can be deployed within a week.