debug of rank: add isRanked function to ItemList. Make sure that sortRankItemList is run once and only once. And sortItemList also calls sortRankItemList implicitly
Item object removes the record 'order': clearly order is an attribute of the list, not of the item of the list
add documents the functions with DOXYGEN
ItemStruct removes the record order
manually tested the invariability of index and ranks with regard to the order of function calling. Needs to write tests