o Major bugfixes:
   - Ignore negative and large timeout values that can happen during a
     suspend or hibernate. These values caused various asserts to fire
     in the circuit build times code, crashing Tor. Bug 1245, bugfix on
     0.2.2.2-alpha.
   - Alter calculation of Pareto distribution parameter 'Xm' for Circuit Build
     Timeout learning to use the weighted average of the top N=3 modes. This
     should improve the timeout calculation in some cases, and prevent
     extremely high timeout values. Bug 1335, bugfix on 0.2.2.2-alpha.
   - Alter calculation of Pareto distribution parameter 'Alpha' to use a
     right censored distribution model. This allows us to remove the synthetic
     timeout generation and instead calculate build timeouts using truncated
     times. Bugs 1245+1335, bugfix on 0.2.2.2-alpha.
   - Keep circuits open (but do not use them) after the circuit timeout for
     up until the time corresponding to the 95th percentile on the Pareto CDF
     or 60 seconds, whichever is greater. This is done to provide better data
     for the new Pareto model. This percentile can be controlled by the
     consensus.

 o Minor bugfixes:
   - Eliminate a case where a circuit build time warning was displayed after
     network connectivity resumed. Bugfix on 0.2.2.2-alpha.

 o Minor features:
   - Add a TIMEOUT_RATE keyword to the BUILDTIMEOUT_SET control port event,
     to give information on the current rate of circuit timeouts over our
     stored history.
   - Add ability to disable circuit build time learning via consensus
     parameter and via a LearnCircuitBuildTimeout config option. Also
     automatically disable circuit build time calculation if we are either
     a AuthoritativeDirectory, or if we fail to write our state file. Bug 1296.