6.0.4

Fixed

• SPF: concatenate TXT character-strings without removing literal quotes or
  backslashes before selecting records, so a split within or immediately after
  v=spf1 is accepted in top-level, include:, and redirect= lookups as
  required by RFC 7208 section 3.3 (#286)
• DNS: escape literal quotes and backslashes in quoted TXT output so payload
  characters remain distinct from string boundaries (RFC 1035 section 5.1)
• DNS: preserve UTF-8 sequences split across TXT byte boundaries, retaining
  the original string lengths for SPF size warnings (RFC 1035 section 3.3)
• DNS: escape linefeeds in quoted TXT output so dnspython can parse it back
  into the original byte strings
• SPF: decode non-digit DNS escapes in quoted input to parse_spf_record()
  so escaped mechanism names and values can be assessed (RFC 1035 section 5.1)
• SPF: accept surrounding spaces, tabs, and line endings in quoted parser
  input without stripping payload whitespace or discarding Unicode and control
  characters between quoted strings