…e to actively cascade to child views. While you could previously use the `isEnabledInPane` property to determine if any ancestor view had been disabled, it was lazily computed and not bindable. With this change, `isEnabledInPane` is updated actively, which means that it can be used to update the child view's display if wanted. For example, a view gets the 'disabled' class if isEnabled is set to false, but it can also add isEnabledInPane as a displayProperty and use it to appear disabled if any ancestor becomes disabled.
This cascading can be blocked by any child view by setting `shouldInheritEnabled` to false, which allows you to set isEnabled on the top pane, but keep a section of child views separately enabled.
Includes unit tests. Closes #638.