[Suggestion] API to freeze specific files (prevent deletion or modification)

In some cases and particularly with Big Files, you would want to prevent the deletion of a user file or even a zite file. For example, if you seed a useful 2go image file and suddenly the user who posted it remove it, you will completely lose the file. I think even if the zite is deleted by the owner (ex: private-key compromised, all data removed), you should be able to prevent update/deletion of some files.

Implementation-wise, each file indexed in content.json could have a "frozen" flag, but no idea about how ZeroNet will share the files between peers if they are locked at a specific version in time (and I don't know if content.json files can be "customized" locally).
Use case: for a zite like ZeroUp, every file you seed could be frozen by default.

I know there are suggestions about versioning, but you can use tools like rdiff-backup if you really want to backup a zite. It's more about trusting your files from not being deleted, as you'd expect with things like torrent.