[TreeTable] An ArrayIndexOutOfBoundsException is thrown when calling getAddedSubList on a Change from TreeTableView's selectedItems.

When handling change notification from TreeTableView's selectedItems, an ArrayIndexOutOfBoundsException can be thrown when calling getAddedSubList on the change. So far, I've only been able to recreate the error after iterating the getRemoved list of items for the change.

Here is a sample case:

https://gist.github.com/ryanjaeb/3271d380d8833d2ca554

Steps to reproduce:

1. Run the example using 8u20-b17.
2. Click on the "name" column to sort the items.

An AIOOBE will be thrown. This does not happen with 8u5:

1. Run the example using 8u5.
2. Ensure "one" is selected before sorting.
3. Click on the "name" column to sort the items.