- When using DISC <call> for a cluster, the specified cluster is well
  disconnected but other clusters beyond this cluster still are in
  memory. Fixed. Thanks SM0RUW & LA3WAA.

- DxNet showed a wrong WWV time if the time was lower than 10. Fixed. Tks
  LA3WAA & SM0RUX.

- SH/A <string> case sensitivity fixed. Tks SM0RUX.

- Added a 30 seconds timeout when the DX database is searched (SH/DX). If the
  DX database file (dx.bin) is very large, it can take a very long
  time to search the entire file on slow computer. It is not needed AMHO
  to keep this database file growing because a very old DX spot (e.g. one
  month or more) is not so usefull anyway. Remamber DxNet can manage only
  one task at once. So if one task take a long time, DxNet can do nothing
  else during this time and users may even be disconnected by the switch
  because there is no activity ! :-) Tks IS0HHA.

- Same for announce database (SH/A).

- If dxnet either receives or sends an initialization sequence request
  (INIT command) it will first remove the whole the users/nodes from the
  initialized link from memory, and inform other adjacents as well. Tks
  SM0RUX.

- Hops database (SH/HOPS) will no more be updated for hop counts for itself
  if the protocol have been looped back (cluster ring / round trip).
  Tks SM0RUX.

- SET/LOG command fixed. Tks OH6NJ and others.

- RCMD now limited to validated sysop only (after a SYS password
  identification sequence) instead of "just declared" sysop. Tks IK5ZUK.

- Same for INIT and RINIT. Tks IK5ZUK.

- DX dupe wasn't well checked if the logger callsign have a ssid different
  than 0. Fixed. Tks SP9UMX.

- Improved annoucement dupe checking. Tks SP9UMX.