First attempt at NSView activation + Xam bug workaround
Cleaned up. Deactivation is triggered when view is replaced with another. Does not get triggered when containing window goes away.
Added an optional IViewFor view parameter to the WhenActivated extension methods to enable caller to specify the view model host. Enables us to work around AppKit limitations.
Adding an optional parameter is a breaking ABI change
Version bump to 6.0.6