Peak Flow Benefit Calculations

[nickrsan]

Peak flow benefit calculations will have the following properties:

1. They can't provide benefit in a vacuum - they need the whole year's time series to provide a benefit calculation, because the amount of daily benefit will change based on how many previous times the flow has been in the peak box.
2. They should have a per-component (or segment, but maybe start with per-component) initial benefit. That is, the amount of benefit for the first time we get that flow.
3. They should have two decay rates - for now, make it linear, but make it a method that can be subclassed to change behavior. The first decay rate handles how much benefit drops for continued days within a peak flow, and the second handles how quickly it drops for each additional discrete peak flow event. I expect linear values would be good because at some point it should drop to be the same (or less) than the value of staying in the baseflow, or else the model will just try to have peak flows all the time.