Log Message:
fix bugs found by gendalia@:
- transition from BBHOME etc to XYMONHOME etc needed to also happen
  in files/xymon.sh
- vmstat on NetBSD has not shown 3 disks in a while already, so
  vmstat trending for NetBSD clients was off. The disk names that
  remain are left unchanged since for existing rrds a change would
  cause failing data submission