fix rebase, use 'object::user:<username>' or 'object::store:<storageid> as storage id, by default use container/bucket name for storageid, make storageid configurable, store user only for HomeObjectStoreStorage, change updateObject() to writeObject()

add autocreate config option for containers, implement autocreate and delete of containers, use generated container names for tests

fix checking unset array values, deduplicate code, remove file from cache if it could not be stored in the objectstore

- the file/folder's permission is now stored in the file cache
- BackGroundWatcher has been removed - this has meanwhile be replaced by occ files:scan which can be executed in a cron jobs
- increase version to trigger database migration