Add a numeric tag property to a layout that we can set/get

[AlanSkyNet]

I can't tell if a layout has been initialized with custom code without creating global javascript variables.

If I can set/get a tag property with a numeric value, I could tell that this layout has been initialized, it may also apply to form and grid objects.

Today I have to create a global variable LayoutPersonFirstPaneInitialized to know if the first pane inside a layout or form has been initialized. With a tag property, I would set it to 1 after initialization and query it's value during the onRefresh event.