Fixed #9871 -- Geometry objects are now returned in dictionaries and tuples...

Fixed #9871 -- Geometry objects are now returned in dictionaries and tuples returned by `values()` and `values_list()`, respectively;  updated `GeoQuery` methods to be compatible with `defer()` and `only`; removed defunct `GeomSQL` class; and removed redundant logic from `Query.get_default_columns`. 


git-svn-id: http://code.djangoproject.com/svn/django/trunk@10326 bcc190cf-cafb-0310-a4f2-bffc1f526a37