Remove old compatibility shims from d.c.gis.

from django.db import connection

if (hasattr(connection.ops, 'spatial_version') and

        not connection.ops.mysql):

    # Getting the `SpatialRefSys` and `GeometryColumns`

    # models for the default spatial backend.  These

    # aliases are provided for backwards-compatibility.

    SpatialRefSys = connection.ops.spatial_ref_sys()

    GeometryColumns = connection.ops.geometry_columns()

:mod:`django.contrib.gis`

^^^^^^^^^^^^^^^^^^^^^^^^^^

* ...

* Compatibility shims for ``SpatialRefSys`` and ``GeometryColumns`` changed in

  Django 1.2 have been removed.

:mod:`django.contrib.messages`

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^