Other flow metrics

Any chance that the USGS developers of this package would be interested in adding the following metrics to this package?

1. **Flow reversal** - number of times per water year that the a trend change occurred in the daily time-step hydrograph (rising to falling limb or falling to rising limb, except for minor variations (<2 percent)
2. **Richard-Baker Index** - mean daily rate of change (absolute value) of daily time-step hydrograph for each water year
3. **TQmean** = fraction of time in each water year that the daily time-step hydrograph exceeds the annual mean discharge for the year
4. **PK2YR**: ratio of the peak flow rate with a 2-year return frequency to the mean baseflow rate during the period October 1 - April 30
5. The ability of the user to pick the threshold for low flow and high flow pulse counts/frequencies (e.g. what if I want my threshold to be 2x the mean annual long term flow rate?)