repo: don't just report user name and email in one field - separate things properly

In the repo RSS feed, report author as
<author>name@example.com (User Name)</author>
instead of using
<dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">User Name &lt;name@example.com&gt;</dc:creator>

And in the ATOM feed with name and email separate:
<author>
<name>User Name</name>
<email>name@example.com</email>
</author>
Instead of
<name>User Name &lt;name@example.com&gt;</name>