Disassociate User Permissions from Document Versioning

A User's permission is removed from a Document when this is reverted to a version where that permission was non-existent.

How to reproduce

• Create a document of any type
• Make changes in the document in order to create a new version 
• Add permission to another user in the Permissions tab
• Back in the View tab, select a prior version (e.g.: 0.1) and click the "Restore" button.

After this last step, the changes to the document should be reverted to the specified version but the Permissions should be independent of versioning.

This occurred with the embedded db (H2).