Utilize select_related() for user & user profiles. This commit also removes the caching of the avatar URL in the avatar template tag. This is because we are now using select_related, so we already have the profile & avatar when we get to the tag. Thus we don't need to waste time querying the cache. Removed an apparently unused member map template as well.

'''
This file contains the automatic admin site definitions for the podcast models.
'''

from django.contrib import admin
from podcast.models import Channel
from podcast.models import Item

class ItemAdmin(admin.ModelAdmin):
    readonly_fields = ('update_date', )

admin.site.register(Channel)
admin.site.register(Item, ItemAdmin)