ideas

  - Clarify that complete algorithms are canonical
  - Break off backwards ecn idea into ideas directory.
  - Define RTT_min
  - cite prop 325
  - Count INTRODUCE1 towards SENDME, don't count SENDME.
  - note optimization for circwindow_inc variability
  - consider limiting the rate of change of circwindow_inc
  - Mention hs-ntor allows extra data fields
  - Mention if we calculate recieve window, it can become negative.
  - Track outstanding sent cells for better BDP estimates.
  - Use min of backoff multiplier vs BDP, not max.
  - We can safely set our initial congestion window much higher than TCP.