Add web based python shell to Melange. It is accessible via http://host/admin/shell url and requires developer rights. Shell project is part of google-app-engine-samples. This commit moves django configuration from main.py to separate gae_django.py module. Shell project has been modified in order to work correctly with django 1.0+. Build script has been updated and includes shell folder and gae_django.py file. http://code.google.com/p/google-app-engine-samples/source/browse/trunk/shell/

# 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