As a Querki user, I should be able to give Reviews of Apps

(User Story, Investigate , Priority: High, Test Status: No automated tests yet , Reported By Justin du Coeur, )
Apps
Summary: Basically, the Review Property should exist on the _App Gallery Entry, and it should be public -- all users should be able to user it.
How do we deal with spam here? The Review needs to be moderated?
Do we want to decouple Ratings and Reviews here, and add Ratings first? That's rather safer.