Replace HomeSettings with Presence Model class. Replace SiteSettings with
Site Model class. Derive Group Model class from Presence, adding the "home
page settings" properties in a Melange site presence to every Group.
Patch by: Todd Larsen
# Getting the normal admin routines, classes, and `site` instance.
from django.contrib.admin import autodiscover, site, StackedInline, TabularInline, HORIZONTAL, VERTICAL
# Geographic admin options classes and widgets.
from django.contrib.gis.admin.options import GeoModelAdmin
from django.contrib.gis.admin.widgets import OpenLayersWidget
try:
from django.contrib.gis.admin.options import OSMGeoAdmin
HAS_OSM = True
except ImportError:
HAS_OSM = False