Allow for extra dynamic fields for the create form
Also some minor cleanups, such as making base.Logic inherit from
object, as per the style guide.
Patch by: Sverre Rabbelier
# 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