Restrict delete for CDAO models

app/models/ability.rb

@@ -11,6 +11,11 @@ class Ability
       can :display, Cdao::Jurisprudence
 
       can :manage, :all
+
+      cannot :destroy, Cdao::Jurisprudence
+      cannot :destroy, Cdao::Library
+      cannot :destroy, Cdao::LibrarySubject
+      cannot :destroy, Cdao::Subject
     end
   end