Alert user of restore overwrite
Delete old vault (preset parent of first file) before restoring
Include backup finish text to short notif text
Merge pull request #42 from Doplgangr/backupImprovement

Perfect!
Fix import screen FC
Fix (dirtily) leave vault bug
Fix BackupDoneEvent not handled,
Since some unknown fragments also gets this event (don't know exact reason behind) without initialized mBuilder.
Add not null checker.