Added a custom tag to display a link to a profile. Refactored the avatar tag to optionally display a profile link around the image. Removed the width and height attributes from the avatar image tag. I think this was causing disk hits whenever those properties were not cached. The avatar tag is now an inclusion tag.

{% load core_tags %}
<p>
<span class="shoutbox-user">{{ shout.user.username }}:</span>
<span class="shoutbox-shout">{{ shout.html|safe }}</span><br />
<span class="shoutbox-date">{{ shout.shout_date|elapsed }}</span>
</p>