Mergeall 3.3 GUI Changes

Mergeall 3.3 expands the scope of its -quiet flag: this flag now silences both per-item backup messages (its former role), as well as Unicode normalization messages (it's new role). To support this, the GUI in 3.3:

See the screenshots below to sample these minor changes in action. All were captured on macOS, and all but one were run from source code on Python 3.8. Most important: the AFTER shot shows the new main window in 3.3. For more fidelity, the app shot compares the current (and Python 2.5-based) app's state, and the run-dialog shots show unrelated wording changes.

Caveats: 3.3's changes, including its new GUI layout, are currently available only in the source-code package. In addition, the GUI's Android fork may never adopt 3.3's changes, because it's sadly become a functional dead end; details and alternatives here and here.