RemoveSelected - Remove selected entries from reference (Shift-Del)

The remove selected entries action will be activated for controls referring to not owning collections, only. When the data source is not a reference or relationship or when the collection does own its instances, the action is inactive and cannot be called.

The action may apply on any kind of list. For multi-selection lists, the action removes all selected entries. For single selection lists or when no entry has been marked as checked (in a check box list), the action removes the currently selected entry.

When no instance is currently selected in the data source, the action will be disabled.

When calling the action, it will remove the currently selected instance without warning or message. In order to receive a warning message before deleting an instance the GUIFramework .Query.Delete option should be set (see "Option browser")