PEP8ification
Fix failing ZA test.

Best to create models with unicode strings.
Fix traceback when saving a Person/Organisation

Currently there is a traceback when saving a Person or Organisation
because the id fields of Positions and Contacts (which are edited inline)
don't get rendered in the inline formset.

In order to avoid this, I've replaced the standard AutoField id for
Positions and Contacts with a subclass of AutoField which is rendered as
a hidden input, and explicitly included the id fields.