ToDo list for smsdaemon:

- SmsPdu: make EncodePdu work without the trailing 0x00 in UDH (multipart) - requires more work on Encode7to8bit
- Option: Use syslog instead of custom logfile
- Create a filtering method:
  Incoming: which phonenumbers are allowed to invoke which plugins
  Outgoing: which phonenumbers are allowed to send to (to avoid loop backs)
- Improve smstool locking method (maybe adopt spooler to use the same)