- Earlier detection and better logging of
      truncated TunnelGatewayMessage and DatabaseStoreMessage
    - Fix and enhance UnknownI2NPMessage implementation
    - Don't deserialize or verify the checksum of the
      embeddedI2NP message in the TunnelGatewayMessage
      at the IBGW, just use UnknownI2NPMessage and pass it along,
      except if zero hop; Still to do: similar thing at OBEP
    - Round expiration times when converting to/from seconds for SSU
    - Cleanups and javadoc