fixes Widget.setChildName()
version bump
adds triggering event about child name change in Widget
eliminates unnecessary removal & addition in Progenitor.setChildName()
adds triggering of events at chilc addition and removal
adds child widget as payload to addition & removal events in Widget
fixes Widget for rendering last child widget
restores removing old child in Progenitor.setChildName() when child by same name already exists
reverts child rename mechanism to remove + add