  o Minor bugfixes (performance, fingerprinting):
    - Our default TLS ecdhe groups were backwards: we meant to be using
      P224 for relays (for performance win) and P256 for bridges (since
      it is more common in the wild). Instead we had it backwards. After
      reconsideration, we decided that the default should be P256 on all
      hosts, since its security is probably better, and since P224 is
      reportedly used quite little in the wild.  Found by "skruffy" on
      IRC. Fix for bug 9780; bugfix on 0.2.4.8-alpha.
