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
