ToDo list for smsdaemon:

- SmsPdu: make EncodePdu work without the trailing 0x00 in UDH (multipart)
  Requires more work on Encode7to8bit
- ModemTransceiver should be able to concatenate multipart sms, before handing them
  over to SmsDaemon
- 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)
- Config file : it should be possible to configure which plugins should be loaded, 
  the plugins should also load parameters from the config.
- when using SmsToolTransceiver, the target phonenumber must include countrycode (45 in DK)
  can we check this in smsdaemon??
- Make a KannelTransceiver class for interfacing with kannel ?