in bookpath selection, show status of book

[bertsky]

When the bookpath contains a lot of directories (for a number of annotators or from a number of documents) it would be helpful if the UI would indicate their annotation status directly in the selection view.

For example, it would be useful to know whether some or all pages have been saved. This could guide which book to select next (without having to remember where work was left off last time or open each book just to check).

This could be implemented with a different background color, or in an extra column.