let the user check for address books

Signed-off-by: Lehner Florian <dev@der-flo.net>
start to implement list_box

Signed-off-by: Lehner Florian <dev@der-flo.net>
flush GTK_LIST_BOX

Signed-off-by: Lehner Florian <dev@der-flo.net>
start to add a new row

Signed-off-by: Lehner Florian <dev@der-flo.net>
add scrolled window for address book list

Signed-off-by: Lehner Florian <dev@der-flo.net>
implement the check option

Signed-off-by: Lehner Florian <dev@der-flo.net>
enable/disable the sync of an address book

Signed-off-by: Lehner Florian <dev@der-flo.net>