Update CGI from version 3.63 to 3.64

Update CGI from version 3.63 to 3.64

    [BUG FIXES]
    - Avoid warning about "undefined variable in user_agent in some cases (RT#72882)

    [INTERNALS]
    - Avoiding warning about "unitialized value" in when calling user_agent() in some cases. (RT#72882, perl@max-maurer.de)
    - Update minimum required version in Makefile.PL to 5.8.1. It had already been
      updated to 5.8.1 in the CGI.pm module in 3.53.
    - Fix POD errors reported by newer pod2man (Thanks to jmdh)
    - Typo fixes, (dsteinbrunner).
    - use deprecate.pm on perls 5.19.0 and later. (rjbs).

    [DOCUMENTATION]
    - Update CGI::Cookie docs to reflect that HttpOnly is widely supported now.