image and author json filesystem import

[thejohnhoffer]

There's a complication when granting permissions to separate directories

[thejohnhoffer]

Instructions for users

• copy OME-TIFF to subfolder of downloads
• then select name for story.json to save within

Local storage

• In addition to continuous writing to story.json, also save to localStorage
• Allow auto-save both in localStorage and filesystem
• Only allow undo history in localStorage