Sort calculation results of a historical discharge calculation based on their start date. Therefore, there are two new inner classes TimerangeItem and HistoricalTimerangeItem that wrap a W, Q, Timerange (and delta Q). WQTimerange and HistoricalWQTimerange now implement a sort() that return the results (TimerangeItem or HistoricalWQTimerangeItem) sorted by their start date.

build with `make datacage-config-manual`