[dev] New turba Driver Proposal

[Damian Alejandro Fernandez Sosa]

Turba has 3 backends prefs, sql and ldap.

I propose to make a turba driver to use an IMAP folder as a new turba
backend.

* all the emails found there are considered a contact.
* the email's From: header is the turba email field  (and also the name
field) using the  "NAME" <email> format

the other fields are in a vcard attachment and the certificate
information in other email part.


* you can add contacts to this backend in 2 ways:
        * copying an email into the folder choosen to act as the turba
backend
        * As usual in turba, This is creates a "fake" email with all the
information in the created email structure (all the turba fields) and
makes an IMAP append to add the contact.



the backend could be "personal"  or "shared" (if that folder is marked
as shared in the IMAP server)



If you like the idea I can make it.

We can make the same thing with kronolith but we need to think the idea
more.