* Added a generic (void *) parameter to the ForEachUser() and ForEachRoom()

* Added a generic (void *) parameter to the ForEachUser() and ForEachRoom()
  callback mechanisms, to allow callers and callbacks to pass arbitrary data
  between each other without requiring TSD variables.
* room_ops.c: eliminated the need for 'FloorBeingSearched' TSD variable
* internet_addressing.c: eliminated 'buffer1' and 'buffer2' TSD variables