title: Insert "http" image in MigraDoc table
body: <p>MigraDoc provides insertion of image when it's in application directory. 
  Example:</p>
  
  <pre><code>Section section = document.AddSection();    
  section.AddImage("../../SomeImage.png");
  </code></pre>
  
  <p>When I add http image path in .AddImage parameter it displays "Image not found." in PDF.</p>
  
  <p>Is there any way to insert http image in PDF generated by MigraDoc?</p>