eds: Don't copy EVCardAttributes at all
eds: Don't copy EVCardAttributes at all

libebook does some icky things with EVCardAttributes it's passed, especially
when calling e_vcard_remove_attribute() (it removes by pointer comparison
and then unconditionally frees the passed-in attribute). Consequently, we
need to do everything we can to avoid copying EVCardAttributes unless we
want double-frees and memory leaks.

renatofilho/folks2,renatofilho/folks,pwithnall/folks,renatofilho/folks,renatofilho/folks,renatofilho/folks,pwithnall/folks,GNOME/folks,GNOME/folks,renatofilho/folks2,renatofilho/folks2,GNOME/folks,pwithnall/folks,renatofilho/folks2