missing safety checks on shift-ctrl selection on listbox

Steps to Reproduce

https://zkfiddle.org/sample/2pvqgk0/18-Another-new-ZK-fiddle

Run fiddle

Select last Listitem

Click button (delete last item)

Shift+Click any Listitem

Current Result

Error: Index: 6, Size: 6

Expected Result

no error

Debug Information

caused by the Listbox._selectUpto function (from SelectWidget)

https://github.com/zkoss/zk/blob/c787afdb2caee30df173da7fa45e00d2c658df08/zul/src/archive/web/js/zul/sel/SelectWidget.js#L878

this._lastSelectedItem is not deleted from Listbox when listitem is removed, Listbox tries to use a non-existing index

Workaround

(see fiddle, commented out)

Secondary issue, related to main issue

If there is no selected element (due to component just having been rendered, and no selection triggered), doing shift+click on an item will select all items from index 0 to target  (see 2nd listbox with selected items content filled onSelect)

However, only the targeted Listitem is marked as selected.

(This is due to the same line of code as the main issue, if no bounding item is found)