unified errorExit function instead of explicite sys.exit calls
add config_file argument to CryptoBoxProps
add getCapacity method to CryptoBoxContainer
removed "classes.txt"
added startup test to CryptoBox
integrate CryptoBoxRootActions into CryptoBox (see example-super.tab for details)
implemented "mount" and "umount" in CryptoBoxRootActions
adapted CryptoBoxRootActions checks to 'super'