Enable preview of CustomControl's template

[roxk]

No description provided.

[roxk]

Blocker: Dictionary containing control template can't be parsed by xaml reader it seems. Bummer. But there should be way around that.

[roxk]

Good news: there was bugs in the XAML trimmer that doesn't preserve namespaces declared at root. This caused TargetType="loca;Foo" to fail to resolve local:Foo since local was removed. Fixing it allowed TargetType to be present in style, and the resource dictionary could be loaded.

There is still the edge case where the namespace is defined in parent scope, but this is very rare in the grand scheme of things and can be fixed later.