Small fix that prevents large files from hogging the session... Just this

should be good for most situations but 1.4.3 maintainers feel free to
do this more comprehensively as per the moodle.org discussion on it.  ;-)

file.php

@@ -54,6 +54,8 @@
         $filename = $fileargs[0];            // Only keep what's before the '?'
     }
 
+    session_write_close();
+
     if (file_exists($pathname) and !is_dir($pathname)) {
         $lastmodified = filemtime($pathname);
         $mimetype = mimeinfo("type", $filename);