Envelope has the same Message-ID, but using other fields from the
envelope, such as From field, is error-prone. They may contain values
different from the message body. As we don't parse the envelope later on,
it is better not to fetch it during prefetch too.
This capability is not used by Delta Chat. Moreover, XLIST is deprecated
in favor of https://tools.ietf.org/html/rfc6154, which should be
supported instead. Delta Chat already looks for \Sent attribute in
get_folder_meaning().
before a message is actually deleted,
we verify that server_folder+server_uid matches the Message-ID,
so that we do not delete the wrong message by accident.
the reason for that is that, to my knowledge, server_folder+server_uid
are not necessarily stable but Message-ID is.
anyway, this check was broken and set the server_uid to 0 in all cases -
where it should be set to 0 _only_ on mismatches.
- recreate the group list more carefully, fixes#985
- resultify a few functions in the dc_receive pipeline
- don't quote displaynames in email-addresses, use utf8, preliminrarily addresses #976
