Project Class Updates

[vkbo]

Some updates to the core project class and how it scans and handles content in the project folder.

Includes:

• A minor rewrite of the old to new file storage location update function.
• Updated the cleanup function for no longer used files.
• Added an accumulated project edit time meta data setting.
• Removed the saving of the expand flag from project files. Files cannot be expanded in the tree.
• Cleaned up the document class open and save now that we only have one data folder.
• Table of contents files are written to the project root folder when the project is closed.