fixes #6519 - updating associations UI

Added associations to the UI:
+ subscriptions to content hosts and activation keys
+ activation keys to content hosts

That's why, when asked about using HTML in a tooltip, I said that we ought to wrap the AngularUI directive in another directive which transcludes the html to be inserted, much like how `alch-edit-custom` works.  That would allow you to keep the html in the html.