Radio buttons should treat the enum value as primal

[scallyw4g]

At the moment the radio buttons are a little weird.

They currently don't treat the enum value they're created from as primal. The proof of this is that if you open two windows that read/modify the same value, toggling a radio button in one does not update the other. This is undesired, and actually a bug. Since the underlying enum value is actually modified, the view that doesn't update is stale, and displaying the wrong value!!

Additionally, radio groups don't display the default value (typically zero), as selected, which smells pretty wrong.