Added lastPublished and language to RSS generator
Use $head->title for RSS Feed title
Reverted back to multi-line template, and added pubDate and guid (url)
Use a switch on $_REQUEST['datalist'] and require admin login on PHP_errors
Added created to update_rss() and added case for PHP_errors in datalist()

Remove xmlns in update_rss(). Was using Atom 1.0

Use `created` for <pubDate> in update_rss().
Fixed using time() instead of date() in update_rss()
Finally got RSS working.

In update_rss(), I was using the wrong date format and had my final
two tags out of order.

Used a validator that confirmed that this is valid.
Updated url in sitemap and RSS

Was using /$url when I needed /posts/$url

This required removing the home page from both... a bigger deal for sitemap
than it is for RSS.