Merge branch 'ks/maint-1.6.0-mailinfo-folded' into maint-1.6.0

* ks/maint-1.6.0-mailinfo-folded:
  mailinfo: tests for RFC2047 examples
  mailinfo: add explicit test for mails like '<a.u.thor@example.com> (A U Thor)'
  mailinfo: 'From:' header should be unfold as well
  mailinfo: correctly handle multiline 'Subject:' header