Refactor the sidebar to use Django templates
With this change the html for the sidebar is no longer generated by
Melange, instead it's delegated to Django (which is what it does
best anyway). The downside is that it is no longer possible to have
arbitrary deeply nested menu's.
# Want to get everything from the 'normal' models package.
from django.db.models import *
# The GeoManager
from django.contrib.gis.db.models.manager import GeoManager
# The GeoQ object
from django.contrib.gis.db.models.query import GeoQ
# The geographic-enabled fields.
from django.contrib.gis.db.models.fields import \
GeometryField, PointField, LineStringField, PolygonField, \
MultiPointField, MultiLineStringField, MultiPolygonField, \
GeometryCollectionField
# The geographic mixin class.
from mixin import GeoMixin