ASA Notes - add pvt/ins to grs corses

add quizzes and study material

tweaks to:
books_products
products_quiz_definitions

  # products for which the user has active subscriptions
  def activated_quiz_products
    seen = {}
    self.subscriptions.each do |s| 
      if s.active_expiry_subscription?
        # don't include groundschool products here
        # removed this restriction for GRS-58
        # if s.product.name !~ /Ground School/
          seen[s.product] = true        
        # end
      elsif s.active_token_subscription?
        seen[Product.find_by_name("Practice Tests")] = true
      end
    end
    return seen.keys.sort_by {|product| product.name}
  end