#437: rose edit: upgrade applications

This closes #437. It adds upgrade functionality to `rose edit`.

The other major change is that there is now a proper distinction between `named` tags (those with proper metadata) and non-named tags (which may represent intermediate steps between released metadata versions).

This can be tested via the `demo/rose-config-edit/demo_meta` suite and the `*-upgrade` apps. The new option is in the Metadata menu of rose edit.

@matthewrmshin, please review.