Export enhancements

Placeholder for notes on Export Enhancements.

Interface (list of function from Collection.php)

 * CollectionAddArticle
 * CollectionRemoveArticle
 * CollectionAddCategory
 * CollectionAddChapter
 * CollectionRenameChapter
 * CollectionSetTitles
 * CollectionSetSorting
 * CollectionClear
 * CollectionSuggestAction (ban, add, remove, undo)
 * CollectionGetBookCreatorBoxContent
 * CollectionGetItemList
 * GetMWServeStatus

irrelevant functions (i.e. interactive mode only):
 * CollectionGetPopupData