title: Fitlering data by "destination-value" of a field
body: <p>Open Graph should use this syntax:</p>
  
  <pre><code>&lt;meta property="og:title" content="This is the title" /&gt;
  </code></pre>
  
  <p>but some website use <code>name</code> instead of <code>property</code> (also stackoverflow, check it out this question html). And I've also seen other parameters, such as <code>data-og</code>.</p>
  
  <p>So, I'd like to select/filter an element with jQuert that contains <code>og:title</code> as value instead of <code>property</code>, because this:</p>
  
  <pre><code>$mypage.filter("meta[property='og:title']").attr("content");
  </code></pre>
  
  <p>won't work for example if I parser a stackoverflow page (which has <code>meta name='og:title'</code>). </p>
  
  <p>How can I do this in jQuery? Filter by "value-destination"? Tried with:</p>
  
  <pre><code>$mypage.filter("meta[*='og:title']").attr("content");
  </code></pre>
  
  <p>but it give to me fields that does not contains <code>og:title</code></p>