1.004 - 2019/02/20
- rename DKIM_* constants and description according to RFC 7601 2.7.1
  DKIM_SUCCESS is now DKIM_PASS etc
  The old constants are still provided for compatibility
1.003 - 2019/02/10
- add Date to headers which should be signed by default
1.002 - 2018/11/15
- small fix authentication_results
- fix if sub filter is used after dkim signatures are already read (like
  from Mail::DMARC::Iterator)
1.001 - 2018/10/27
- return needed DNS queries as soon as possible
- verify signature as soon as possible (return errors early)
- add result and authentication_results methods
1.000 - 2018/10/26
- when signing make h_auto the default to get secure header protection
- h_auto and h can be given together when signing and h can include additional
  headers not automatically added using h_auto
0.017 - 2018/10/25
- only warn on incomplete field protection if there is actually a critical
  field unsigned and not already if the signature would allow such addition
- additionally warn if 'l' is used and non-white-space is outside the
  body signature
0.016 - 2018/09/25
- detects if header field protection is incomplete, check VerifyResult::warning
- small improvements to scripts
0.015 - 2016/12/18
- fix signing/validation: only a single header (starting from the bottom) should
  be checked for each entry in [h]eader.
- option `h_auto` to automatically create a useful [h]eader entry when signing
- fixed problem with breaking long lines which made mail header invalid (missing
  space in folded line)
- new scripts/sign.pl for signing mails
- no more endless loop on broken input mails in scripts/validate-emails.pl
0.014 - 2016/06/14
- leave arguments for next as they are, i.e. don't work on alias for(@_) and
  thus inadvertantily change the buffer in the caller
0.013 - 2015/12/16
- make parse_taglist public
0.012 - 2015/11/20
- added filter argument so that for example only signatures matching the domain
  of the From header will be checked
0.011 - 2015/11/18
- make interface more similar to Mail::SPF::Iterator, i.e. everything is done
  through a single method C<next>
0.010 - 2015/11/17
- initial release
