Drop pre-rendered html: User.bio_html

After a bit of discussion, we decided to drop the
pre-rendered html from the database and render it on
the fly.

In another step, we will use some proper caching method to
cache this stuff.

This commit affects the User.bio_html part.

mediagoblin/edit/views.py

@@ -171,8 +171,6 @@ def edit_profile(request):
         user.url = unicode(request.POST['url'])
         user.bio = unicode(request.POST['bio'])
 
-        user.bio_html = cleaned_markdown_conversion(user.bio)
-
         user.save()
 
         messages.add_message(request,