tor-parallel-relay-conn/changes/bug17194

  o Minor feature:
    - When logging to syslog, allow a tag to be added to the syslog
      identity ("Tor"), i.e. the string prepended to every log message.
      The tag can be configured by setting SyslogIdentityTag and defaults
      to none.  Setting it to "foo" will cause logs to be tagged as
      "Tor-foo".