added support for postgis

[fission6]

added support for postgis2.0 utilizing code here:
https://code.djangoproject.com/ticket/16455

[stringfellow]

bump

[DemersM]

This workaround was working correctly with Django 1.4.4 but since Django 1.5 there is errors when creating indexes:

Installing indexes ...
Failed to install index for shapefile.Feature model: column "geom_point" of relation "shapefile_feature" already exists CONTEXT: SQL statement "ALTER TABLE public.shapefile_feature ADD COLUMN geom_po
int geometry(Point, 3857)" PL/pgSQL function addgeometrycolumn(character varying,character varying,characte
r varying,character varying,integer,character varying,integer,boolean) line 110 at EXECUTE statement
SQL statement "SELECT AddGeometryColumn('','',$1,$2,$3,$4,$5, $6)"
PL/pgSQL function addgeometrycolumn(character varying,character varying,integer, character varying,integer,boolean) line 5 at SQL statement

Installed 0 object(s) from 0 fixture(s)

Something need to be updated in the postgis creation.py?