Remove 'python -c'

You should have either `python -c` or '>>>', but not both.  I'm not sure whether "$ python -c 'import this'" or '>>> import this' is better, but the current version is definitely wrong.
Merge pull request #152 from akaptur/remove-python-command-with-python-prompt

Remove 'python -c'
Update AUTHORS.rst
Adding documentation for django.db.models.Model._meta
Documenting Model._meta.auto_created
Documenting Model._meta.auto_field and Model._meta.has_auto_field.
Making django sphinx roles like :setting: work in the django-admin2 docs.
Fixing intersphinx link to django docs.
Documenting Model._meta.concrete_model, installed, model_name, pk, virtual_fields.
Use same ReST syntax as django docs do for _meta attributes.