Currently the ArchiveInterface methods require either a QStringList or a QVariantList with the list of files to work on.

We should replace this with something:

1. More consistent
2. With more informations for the jobs, i.e. with metadata about the entries

In other words, we need to pass a list of ArchiveEntry objects to the API methods. Ideally ArchiveEntry should become a proper class and incorporate the fileRootNodePair logic.

For example, this will be needed to fix bug #363368.