I guess that versioning its also a very important thing in a Backup System.
Yes, versioning is important.
We plan to add this feature but we can’t give you a time estimation when it will be available.
Thanks
I understand. Please keep us posted. 
what is versioning
same question here… whats that??
File versioning is a set number of older copies of files that are kept when a specific file is modified.
For example, you have your file named: MyHomeWork.doc
On May 1st, you created that file and started to work on your homework.
Then, yesterday (May 13th), you continued working on your homework adding more data to the same file.
Then tomorrow (May 15th), you finish your homework and save the completed file.
In this simple scenario, FILE VERSIONING will allow you to have three versions of the same MyHomeWork.doc file.
This completes a Backup system. For example: if you have backed up a damaged document by mistake, the wrong version of your file will be stored in your backup which means that the content will be definitely lost.
With a file versioning backup (a.k.a multi versioning backup) you can avoid such a scenario. It enables you to store and restore a file in serveral versions. So, you can easily restore an older version of your file.
Maybe this Dropbox link can help you understand better.
okay that will be great addition… will older version file take up space?? or it will be in separate space apart from provided 5GB??
Yes, of course it will take space.
A good file versioning system should only store the data that is different in every file version.
Using the example I gave you before… instead of copying 3 times the file, its always better to backup only the changed data that is different between versions…
thanks for info fren