title: Query (M:N) ordered by relationship attribute
body: <p>I have a simple many-to-many E-R described as below:</p>
  
  <p>Model order.rb:</p>
  
  <pre><code>class Order &lt; ActiveRecord::Base
    has_many :cronologies
    has_many :statuses, :through =&gt; :cronologies
  end
  </code></pre>
  
  <p>Model cronology.rb:</p>
  
  <pre><code>class Cronology &lt; ActiveRecord::Base
    belongs_to :order
    belongs_to :status
    validates_uniqueness_of :order_id, :scope =&gt; :status_id
  end
  </code></pre>
  
  <p>Model status.rb:</p>
  
  <pre><code>class Status &lt; ActiveRecord::Base
    has_many :cronologies
    has_many :orders, :through =&gt; :cronologies
  end
  </code></pre>
  
  <p>This code below lets me get all statuses assigned to an order.</p>
  
  <pre><code>@order.statuses
  </code></pre>
  
  <p>...but how to get statuses ordered by the "created_at" attribute of the cronology table?</p>