SAM v3.3: Fixes after testing

- Set Master properties in handler, not in session, so they take
- Create subhandlers for the subsessions
- Create socket manager with preferred createDisconectedManager()
  so we get exceptions
- Fix check for master session
- Enhance error messages
- Add basic master session test for SAMStreamSend
- Add check for DESTINATION in SESSION ADD
- Don't return DESTINATION in an I2P_ERROR response
Next to do: master support in SAMStreamSink