TFC-12136 Removing all the PropertyChangeEvent dispatches which have no value set for property and oldValue, and the itemUpdated() calls in collections (which yield the same type of events) when they come after updates to object's public and bindable properties, because that makes the dispatches superfluous. (The ones I'm leaving in are the ones after updating private properties on objects, so after bypassing the bindable getters and setters, e.g. in AbstractEmployeeTimeAllocationGroupTO; and the ones I don't have time to understand why they're there.) As a result, IMulticurrencyLineItem does not need to extend IEventDispatcher anymore.
NOTES: -see the comment in this ticket for why it should be pretty safe to do this. -also made some minor refactoring where appropriate.
FLEX-34854 First unit test and implementation of watching for changes in complex fields. Also, ComplexSortField now caters for the case when the field name is null. NOTES -Changes are monitored for the objects which existed in the collection before the sort was applied, not for the new ones. This is to follow. -The watching functionality will be externalized from ListCollectionView in the following commits.