title: Issue with & in URL using simplexml_load_file
body: <p><code>simplexml_load_file()</code> does not load XML file when the URL includes an ampersand symbol. I have tried two examples with and without ampersand:</p>
  
  <pre><code>$source1 = simplexml_load_file("http://www.isws.illinois.edu/warm/data/outgoing/nbska/datastream.aspx?id=ncu");
  print_r($source1); //works
  
  $source2 = simplexml_load_file("http://forecast.weather.gov/MapClick.php?lat=38.8893&amp;lon=-77.0494&amp;unit=0&amp;lg=english&amp;FcstType=dwml");    
  print_r($source2); //no output
  </code></pre>
  
  <p>First example works well as it does not includes ampersand, but the second example does not work as it include ampersand.</p>
  
  <p>I have referenced 
  <a href="https://stackoverflow.com/questions/7806458/simplexml-load-file-with-ampersand-in-url-with-solr">simplexml_load_file with &amp; (ampersand) in url with Solr</a> and <a href="https://stackoverflow.com/questions/16795631/simplexml-load-file-ampersand-in-url">simplexml_load_file ampersand in url</a> but it did not work.  </p>