title: sorting an associative array by boolean field
body: <p><code>$list</code> is populated thusly: -</p>
  
  <pre><code>$list[$i++] = array(
      "date" =&gt; $date,
      "desc" =&gt; $desc,
      "priority" =&gt; $priority
  );
  </code></pre>
  
  <p><code>$priority</code> is set to <code>TRUE</code> if it matches some criteria.</p>
  
  <p>I'd like the <code>$list</code> to be sorted with rows that have a priority <code>TRUE</code> at the top.</p>
  
  <p>The list is already sorted by date which I wish to preserve.</p>