Open Recent Folder list

[jordanrobot]

• Available from File menu.
• Show in a flyout menu item "Recent Folder"
• Shows the recent 10 opened folders.
• Duplicate folders should not be listed, only 1 listing per folder.
• This should behave just like the Recent Files feature (PR 50); please look to this implementation for an idea of how this should work.
• Folders that the user selects that no longer exist: show an error message in the status bar and remove the folder from the list.