Hover Behvaior - Cursor/Widgets Interact When Underneath Another Widget

[jcemerson]

Issue:

When a popup is open or a widget (e.g. a button) is nested inside of another widget (e.g. treeview node), the "lower" widget and cursor are interacting, despite another layer being over top of it.

Expected Behavior:
The widget on top needs to terminate the cursors interaction with widgets layered below it.