netclientclock: Filter RTTs based on the median of the last RTTs before considering them at all
netclientclock: Filter RTTs based on the median of the last RTTs before considering them at all

This improves accuracy on wifi or similar networks, where the RTT can go very
high up for a single observation every now and then. Without filtering them
away completely, they would still still modify the average RTT, and thus all
clock estimations.

jpxiong/gstreamer,centricular/gstreamer,StreamUtils/gstreamer,centricular/gstreamer,StreamUtils/gstreamer,jpxiong/gstreamer,StreamUtils/gstreamer,jpxiong/gstreamer,centricular/gstreamer,shelsonjava/gstreamer,shelsonjava/gstreamer,StreamUtils/gstreamer,centricular/gstreamer,krichter722/gstreamer,krichter722/gstreamer,krichter722/gstreamer,StreamUtils/gstreamer,krichter722/gstreamer,shelsonjava/gstreamer,centricular/gstreamer,jpxiong/gstreamer,jpxiong/gstreamer,shelsonjava/gstreamer,krichter722/gstreamer,shelsonjava/gstreamer