Clean up feed items: part 2

As stated in my previous cleanup here is the next patch in my series of Drupal markup cleanups.

This patch fixes the following:

- cleans up specific feed item pages
- uses admin medium date setting instead of a hardcoded one
- adds some missing HTML filters to prevent possible vunerbilities
- improves generated HTML for better semantics and theming

(note CSS classes follow suit with classes used in previous post, to try and clean up the naming convention and make it consistent)

Before code:

<div class="news-item">
 <div class="date">02:21</div>
 <div class="body">
  <div class="title"><span class="source"><a href="/?q=aggregator/sources/5" >NPR</a>:</span>
<a href="http://www.npr.org/templates/story/story.php?storyId=5160916&amp;amp;ft=1&amp;amp;f=1001">GOP Pushes Lobbying Reform in Scandals&#039; Wake</a></div>

  <div class="description">Republican congressional leaders outline proposed changes in the way Congress interacts with lobbyists, including banning privately funded travel by members of Congress. The proposed changes come in the wake of lobbyist Jack Abramoff's guilty plea and other GOP-related corruption charges.</div>
  <div class="categories">Categories: <a href="/?q=aggregator/categories/1" >News</a></div>
 </div>
</div>

New code:

<div class="feed-item">
<h3 class="feed-item-title"><a href="http://www.npr.org/templates/story/story.php?storyId=5160916&amp;amp;ft=1&amp;amp;f=1001">GOP Pushes Lobbying Reform in Scandals&#039; Wake</a></h3>
<div class="feed-item-meta"><a href="/?q=aggregator/sources/5" class="feed-item-source">NPR</a> - <span class="feed-item-date">1 hour 55 min ago</span></div>
<div class="feed-item-body">Republican congressional leaders outline proposed changes in the way Congress interacts with lobbyists, including banning privately funded travel by members of Congress. The proposed changes come in the wake of lobbyist Jack Abramoff's guilty plea and other GOP-related corruption charges.</div>
<div class="feed-item-categories">Categories: <a href="/?q=aggregator/categories/1" >News</a></div>
</div>