Only export visible objects

Currently, the 'Excel export all objects in document' may accidently export objects not used in current layout or not used at all (unused objects).

When users are exporting to Excel from TARGIT today, it should be the wysiwyg experience. Due to evolution, you can accidentally export content that is not visible in a layout. Furthermore, when saving a document, it would be nice to have the option to have your unused list of objects purged.