- Move BWLimits and DestLookup message support from
        I2PSimpleSession to I2PSessionImpl
      - Include the Hash in the DestReplyMessage on a failed lookup
        so the client may correlate replies
      - Add support for parallel lookups and BWLimits requests
      - Add support for specifying the timeout for DestLookups
        (can only be smaller than the router timeout for now)
      - Extend dest lookup router timeout from 10s to 15s