Now clicking cancel button returns user to previous page. Fixes issue 569.
If you don't want that behaviour you can define cancel_redirect and user will be redirected to given url on "Cancel" button click instead of redirecting to previous page.
Patch by: Daniel Hans & Pawel Solyga
# Until model subclassing is a possibility, a mixin class is used to add
# the necessary functions that may be contributed for geographic objects.
class GeoMixin:
"""
The Geographic Mixin class provides routines for geographic objects,
however, it is no longer necessary, since all of its previous functions
may now be accessed via the GeometryProxy. This mixin is only provided
for backwards-compatibility purposes, and will be eventually removed
(unless the need arises again).
"""
pass