  o Minor features:
    - When we fail to initialize Libevent, retry with IOCP disabled so we
      don't need to turn on multi-threading support in Libevent, which in
      turn requires a working socketpair().  This is a workaround for bug
      4457, which affects Libevent versions from 2.0.1-alpha through
      2.0.15-stable.
