Support vCard v4.0 RFC 6350

In vCard 3.0 the format of the PHOTO attribute is (https://tools.ietf.org/html/rfc2426#section-3.1.4): PHOTO;ENCODING=b;TYPE=JPEG:MIICajCCAdOgAwIB...

In vCard 4.0 the format of the PHOTO attribute is (https://tools.ietf.org/html/rfc6350#section-6.2.4): PHOTO:data:image/jpeg;base64,MIICajCCAdOgAwIB...

When EDS downloads a vCard 4.0 it does not display the photo. When Evolution edits the contact and it is uploaded to the server, the PHOTO property is kept as it was in the original, but VERSION is changed from 4.0 to 3.0 and this does not work.

According to my finding, EDS does not send Accept: text/vcard; version=3.0 to the server, to ask it to convert the data to 3.0, as https://tools.ietf.org/html/rfc6352#section-5.1.1 suggests.

Apart from this the server I use ignores Accept: and the strategy for EDS should be anyway to understand vCard 4.0.

Please teach EDS to understand PHOTO from vCard 4.0, and when uploading an image in vCard either upload VERSION: 4.0, e.g. when the downloaded data was 4.0, or upload version 3.0, but convert the photo to 3.0 format.

before.vcf contains the data on the server, before EDS has downloaded them.

after.vcf are the data after EDS has modified them.