Couple of new features for new release of UP4DAR OS

Added:
- Software timer (for internal use)
- DNS Cache (for internal use)
- Syslog (for debug proposes)
- NTP Time Update
- APRS: APRS-IS Position Reporting
- D-PRS: DV-A mode (as part of APRS)
- Slow Data: code separated from DCS (improvements)
- DCS/XRF client (improvements)