added MovingMedian class, but not using it

added packet type/time data collection to DatagramProcessor and
post-execution prints of that info.
extra commit of previous commit?
changed MovingMedian to MovingPercentile
re-enabled piggy-backing in OctreeSendThread
cleaned up debug statements

also reorganized MovingPercentile a little bit
more cleanup
more cleanup again
more cleanup 3
changed MovingPercentile to use QList
MovingPercentile .size() consistency
MovingPercentile moved else to same line as }
added tests for MovingPercentile
Merge pull request #2981 from wangyix/master

added MovingPercentile for filtering bad clockskew values for Node