sfqCoDel now inherits from LinkAwareQueue.
Ensure base class ctors are called; update service rate universally.
Move ewma functionality into a class of its own.
Move arrival, service and link rate estimators into FlowStats.
Set initial values more carefully for all estimators.
Add ewma-estimator to Makefile.in. Current estimator seems too harsh on TCP.
Setup fwd and rev links for CellLink separately with SFD only on fwd.