Get access to the security scope resource when opening files with a sandboxed Mac Store app

When using the QFileOpenDialog with a sandboxed Mac App Store app then the scope is not saved, e.g. when the application is closed and re-opened then the file cannot be accessed unless the file open dialog is shown again.

Apple provides a mechanism called "bookmarks" (entitlement "com.apple.security.files.bookmarks.document-scope" and "com.apple.security.files.bookmarks.app-scope") to remember opened files.

Access to the files can be gained using the "startAccessingSecurityScopedResource" function which takes the file url (tyoe NSUrl) as arguement which is provided when opening the file the first time.

Qt should somehow provide means to get this access url and also offer means to pass this url for opening a file.