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.

"""
Urls for the core application.
"""
from django.conf.urls.defaults import *

urlpatterns = patterns('core.views',
    url(r'^markdown_help/$', 'markdown_help', name='core-markdown_help'),
    url(r'^ajax/users/$', 'ajax_users', name='core-ajax_users'),
)