Creates vcards without N field

[AutoImport-chrysn]

with the contact editor shipped with the sony xperia m and davdroid, the following vcard gets uploaded to a calypso server:

BEGIN:VCARD
VERSION:3.0
UID:14d8467d-1404-4c7f-b78b-d61cb4e31ac0
FN:Test3 Suffix Only
PRODID:DAVdroid/0.7.1 (ez-vcard/0.9.6)
REV:20150318T161127Z
END:VCARD

admittedly, the vcard was created by only filling the phonetic suffix name, but that’s likely to be a user error, and causes the server to reject it on grounds of violating the requirements of RFC 2426 (3.1.2 “N Type Definition”: The property MUST be present in the vCard object.).

please consider adding an empty N line in such cases (“N:;;;;” if i’m counting correctly) or storing contacts as vcard 4.0 (RFC 6350), where the N is optional.

[rfc2822]

The N property will now always be generated if there’s only a prefix or suffix present, too.

For contacts without any name, it doesn’t make much sense to generate N, because many servers will deny contacts with empty FN and N.

In this case the only workaround is to specify a name.