Expose "Show cclink" to Wng actions (on node view)

The current implementation of CCLinks is too inflexible because their visibility is solely dependent on role Access Control settings.

It should be possible to selectively show links based on Wng conditions, in response to node view events. With the events/actions framework you already have in place, you could probably implement this almost effortlessly!

Sample use cases: Only show a "Submit for approval" link when the current user needs approval to publish, and the content has been modified. Only show a "Publish" link when the current user is allowed to publish and the content has been modified.