Log Message:
Update to 1.021

Upstream changes:
1.021     2017-08-02 19:35:56-04:00 America/New_York
        - reject non-ASCII and control characters in strict mode (thanks, Pali
          Roh獺r)

1.020     2017-07-25 12:39:31-04:00 America/New_York
        - unbreak Email::MIME (which violates encapsulation (again))
        - eliminate some @_ / $_ confusion

1.019     2017-07-06 16:06:19-04:00 America/New_York (TRIAL RELEASE)
        - better parsing all around, thanks to Pali Roh獺r:
        - support for RFC 2231 (character set and parameter continuations)
        - support for RFC 2822 comments
        - we only Carp if header-parsing fails now
        - we're more lenient in dealing with spaces around tokens