When constructing the sidebar don't overide 'sidebar'
Instead specify 'sidebar_additional' and include it even if there
is a 'sidebar' defined.
Patch by: Sverre Rabbelier
# Geo-enabled Sitemap classes.
from django.contrib.gis.sitemaps.georss import GeoRSSSitemap
from django.contrib.gis.sitemaps.kml import KMLSitemap, KMZSitemap