Add support for resolving references between resources in a bundle

[ewoutkramer]

(discussed during the Atlanta .NET usersgroup meeting)

Consider a new property on resourcereference for the “instance” that provides immediate location of the contained/bundled item.

HAPI does this, it resolves within Bundle and from a resource to its contained resources. Will not resolve references to resources out of that scope, since that would involve "lazy loading" by doing http requests.

[ewoutkramer]

Since I have now implemented this for resolving within an instance (say a Bundle) based on IElementNavigator. It might be possible to invoke this code from a Bundle or any resource, so let's investigate that.