Refactor ActionMessage to target DependencyObject.

[nigel-sampson]

Currently ActionMessage inherits TriggerAction<FrameworkElement>, this means in the new WinRT environment we can't use message bindings on non framework elements such as Flyout.

Would need to have ActionMessage use some progressive enhancement to light up functionality if the attached target is a Framework Element.

This would light up functionality such as #236

We could also expand BindingScope to return named non Framework Elements (also a lot of work).

[mms-]

New to Caliburn Micro. Seems this is needed to allow tapped event binding on HamburgerMenuGlyphItem in UWPCommunityToolkit?

For now can we do the binding based on the item datatemplate? But how to have it call the action defined on the HamburgerMenuGlyphItem x:Name? This is in UWP so <i:Interaction.Triggers><i:EventTrigger EventName="Click"> does not exist? Any way to do this with XAML behaviors?

[mvermef]

The reason for the tapped not working is there is no convention built in for those controls. Secondly, datatemplates can be a pain the in ass for triggering events with CM, you might have to play around with Action.TargetWithoutContext