* perl/Amanda/Changer.pm: Set storage_name to "NO-STORAGE" if there is
  no storage.
* perl/Amanda/Changer/aggregate.pm, perl/Amanda/Changer/disk.pm,
  perl/Amanda/Changer/multi.pm, perl/Amanda/Changer/robot.pm:
  Keep a current slot by config/storage/changer.


git-svn-id: https://svn.code.sf.net/p/amanda/code/amanda/trunk@5392 a8d146d6-cc15-0410-8900-af154a0219e0