Fixed #11353 -- `GeometryProxy` descriptor no longer chokes when accessed from...

Fixed #11353 -- `GeometryProxy` descriptor no longer chokes when accessed from a class rather than an instance, thanks yml and Tobu; removed unnecessary imports from `types` and cleaned up whitespace.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@12584 bcc190cf-cafb-0310-a4f2-bffc1f526a37