* Major rework of handling for sample population mandatory errors over compatible but not equal role players. Fixes in [1521] began this process, but missed a number of cases. Population errors now require compatibility and will be reported against the nearest single shared supertype instead of the subtype instances. Reporting on the subtype instances was an error per subtype for the same missing instance.
* Modified where population uniqueness errors are displayed. These no longer display on the object type. This display was redundant with the fact types, and the object type shapes were not correctly updating the error display.
* Compact error text (shown in the Error Validation) was using the wrong text for partial fact population errors.
* Major rework of element deletion handling to handle references-to-references (begun in [1519]) and recursive deletion of elements in deleted lists. The INotifySurveyElementChanged.ElementDeleted(element,preserveReferences) notification has been eliminated in favor of new interfaces that allow the elements to decide when a reference to an element deleted from its primary location in a tree will continue to be tracked by the tree. This allows a live element to be cleanly moved into a different primary display location in the tree.
* Handle element equivalence for subqueries. This allows derivation rules with subqueries to be dragged between models without duplicating the subqueries and referencing paths. The powers of 2 get large very quickly, so remerging referenced fact types with subqueries could result over time in an excessive number of duplications.
* Eliminated HashCodeComparer. Hash codes are not unique and should not be used for comparisons that require uniqueness. This was used only for comparing ModelElement instances, all of which have unique identifiers. Replaced with ModelElementIdComparer.
* Double-clicking a role in a fact type for error activation would activate the first error in the role list plus the first error in the fact type list. This is related to a bug in the DSL framework code that deactivates an active mouse action at the end of a 'Handled' double click event. Given that many of the NORMA error handlers are triggered by double clicks and intentionally activate mouse actions, the 'Handled' property of the event cannot be set. An alternative mechanism for when a double click has been handled was added to the fact type shape.
* In an object type shape, selecting the shape and typing or pressing F2 would immediately interact with the name field. This wasn't working for a fact type shape displayed as an object type, which is supposed to have the same behavior as an object type shape. One line fix (return a different default shape field in this case).
