title: doc-view-mode broken after OS X upgrade
body: <p>I recently updated OS X and now my Emacs install cannot open PDFs.  I get the error message </p>
  
  <pre><code>No PNG support is available, or some conversion utility for pdf files is missing.
  </code></pre>
  
  <p>when trying to switch to doc-view-mode on a PDF.  This was working before the upgrade but now I can't figure out what's wrong.  I made sure I had xpdf and ghostscript installed through brew.</p>
  
  <p>Does anyone know how to fix this?</p>