RFR: 8196065: ListChangeListener getRemoved() returns items that were not removed. [v6]

[Michael Strauß]

> The documentation for `ObservableListBase.nextRemove` states that a single change always refers to the current state of the list, which likely means that multiple disjoint removed ranges need to be applied in order, otherwise the next change's `getFrom` doesn't refer to the correct index.
> 
> `SelectedItemsReadOnlyObservableList` doesn't apply removals to `itemsRefList`, which means that subsequent removals will refer to the wrong index when retrieving the removed elements. This PR fixes the calculation of the current index.

Michael Strauß has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 10 commits:

 - Merge branch 'master' into fixes/JDK-8196065
   
   # Conflicts:
   #	modules/javafx.controls/src/test/java/test/javafx/scene/control/MultipleSelectionModelImplTest.java
 - Merge branch 'master' into fixes/JDK-8196065
 - Merge branch 'master' into fixes/JDK-8196065
   
   # Conflicts:
   #	modules/javafx.controls/src/main/java/javafx/scene/control/ControlUtils.java
 - Cleanup
 - Fixed clear-and-select change notification
 - Add failing tests
 - Cleanup
 - Added tests
 - Fix incorrect index when multiple remove changes are handled in SelectedItemsReadOnlyObservableList
 - Add failing test

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Changes: https://git.openjdk.java.net/jfx/pull/478/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jfx&pr=478&range=05
  Stats: 350 lines in 8 files changed: 328 ins; 2 del; 20 mod
  Patch: https://git.openjdk.java.net/jfx/pull/478.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/478/head:pull/478

PR: https://git.openjdk.java.net/jfx/pull/478