nvda

04b75bb7 - Correctly detect next selected slide when deleting a slide in PowerPoint's thumbnails view. Fixes #3415.

Correctly detect next selected slide when deleting a slide in PowerPoint's thumbnails view. Fixes #3415. Specifically: * bind documentwindow's selectionChange script to delete and backspace. * Slide NVDAObject's name property: catch COMError when fetching slideNumber (this was already done for title)