Added Cycle.get_slope_around_percentage, along with Band.count which returns the number of points contained within the Band.
Adding the methods needed in order to sanitize a CycleList of useless cycles.  Symbols will be needed to define thresholds, or some other percentage or integer value.  Attempting to design a way to specify sanitation threshold.  Afterwards, output from the RoftForCycleList class will start being useful!