[registry] backout 120c7ea6e1fa: errors should not pass silently
Catching ImportError silently while loading files has too many side effects.
(e.g. if system hooks / entities can't be registered).
<div id="ajaxroot">
<div class="ajaxHtmlHead">
<script src="http://foo.js" type="text/javascript"> </script>
<link rel="stylesheet" type="text/css" media="all" href="qunit.css" />
</div>
<h1>Hello</h1>
</div>