this lets the users manage changers and lets them view the status of one
by having an overview of:
* slots for tapes
* import/export slots
* drives
lets the user:
* barcode-label all the tapes in the library
* move tapes between slots, into/out of drives
* show some basic info when a tape is loaded into a drive
* show the status of a drive
* clean a drive
Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
