#14 abook: option to parse cc: addresses in --add-email

[Frank Ch. Eigler]

It would be helpful to let the addressbook accumulate addresses that show up in the cc: headers of incoming emails too, not just their originator. There doesn't seem to be a way of doing that now.

[Raphaël]

Fixed by Corey Minyard in 804f03b37fec3fe0a274cd89ec27d2879a0a5afe