Fixes message display after action handling.

Calls unicode to force encoding of object name to a localized
unicode string. Also fixes deleted object count by saving
len(queryset) to a local var before calling queryset.delete(), as
the len after queryset.delete() is always zero.
Merge branch 'bugfix/delete-action-message-display' of git://github.com/chrislawlor/django-admin2 into chrislawlor-bugfix/delete-action-message-display
small correction on model naming
Use PK instead of ID in the model list view and template.
Add Ben Tapin to authors
Implementing a class-based permission handling.
Moving permission logic of views into its own mixin. Also allow to check permission on other views via the PermissionMixin.
Adding the ability to check for permissions in templates.
Setting up autodoc for the docs.

For this to work you need to install sphinx in your virtualenv. It's added to
the requirements.txt so just run: pip install -r requirements.txt
Adding reference documentation for permission handling.