Replace uint64_t with double since ns timestamps are double
Modify QdelayEstimator to work with ns2 timestamps
Change ctor and function signature
Implement get_median_delay based on
https://github.com/anirudhSK/cell-codel/blob/master/schism/src/scheduling-algms/tail-scheduler.cc#L72
Call resetIterator before traversal; else iterator value is defined
Awful bug; delays were being set to zero.
Rename get_median_delay to get_delay_percentile; more accurate delay calc