include_models is missing from options in graph_models.py

```
Need to add something like:

 make_option('--include_models', '-i', action='store', 
             dest='include_models',
             help='Specify which models to include.'),

in django_extensions/management/commands/graph_models.py

Using django-extensions 0.4.1
```

Original issue reported on code.google.com by `Doug.Bl...@gmail.com` on 12 Sep 2009 at 8:22
