* Add a trend check before declaring joint queuing region.
Seeing cases where the propagated queuing delay drops from one group to
next. Both groups are above threhold. It also recovers majority of the
time. So, introducing a trend check before declaring that queuing delay
is in joint queuing region. It is set 0.8 by default which means the
queueing delay should be trending up strongly before being declared
joint queuing region.
* deps