o Minor bugfixes (connection lifespan): - Allow more control over how long TLS connections are kept open: unify CircuitIdleTimeout and PredictedPortsRelevanceTime into a single option called CircuitsAvailableTimeout. Also, allow the consensus to control the default values for both this preference, as well as the lifespan of relay-to-relay connections. Fixes bug 17592; bugfix on 0.2.5.5-alpha. - Increase the intial circuit build timeout testing frequency, to help ensure that ReducedConnectionPadding clients finish learning a timeout before their orconn would expire. The initial testing rate was set back in the days of TAP and before the Tor Browser updater, when we had to be much more careful about new clients making lots of circuits. With this change, a circuit build time is learned in about 15-20 minutes, instead of ~100-120 minutes.