[Evolution-hackers] Required fields support for address book

[Sivaiah <snallagatla novell com>]

Hi,

I have added the required fields support to address book component to
HEAD. Now backends in e-d-s can specify the list of contact fields that
should be present for them to be able to create a contact in
e_book_backend_*_get_required_fields . Clients can acess them using
e_book_(async)_get_required_fields. I have made changes in contact
editor to check for presence of all required fields and otherwise prompt
an error message with missing field name. I have also changed all the
backends to return required fields. Using this we can prevent and fix
bugs like http://bugzilla.ximian.com/show_bug.cgi?id=31021


Siva