title: Scope based on many possible exclusions?
body: <p>How do I create a scope that basically says this:</p>
  
  <pre><code>scope :filtered, where('status != one string, another string, yet another, yep, even more')
  </code></pre>
  
  <p>So basically saying "status does not equal any of the following strings."</p>
  
  <p>And that list of strings will expand over time.</p>
  
  <p>Note, I'm using PostgreSQL.</p>