[Cake] adding dropped bytes and number of active flows to the cake output stats

[Dave Taht]

I think having these would be a good idea.

Tracking peeling also might be of use.... ( I think I have a
preference for 250usec rather than 1ms at this point, although I
imagine it peels like crazy with lots of flows. Another thought is
that the quantum could be dynamic based on the number of flows extant)

-- 
Dave Täht
worldwide bufferbloat report:
http://www.dslreports.com/speedtest/results/bufferbloat
And:
What will it take to vastly improve wifi for everyone?
https://plus.google.com/u/0/explore/makewififast