fixed: "Warning: Use of "ref" without parentheses is ambiguous"

perl5211delta: Support for "?PATTERN?" without explicit operator has been removed
set airplane to false if DZIL_AIRPLANE is defined and false
bump minimum version to get various fixes
Dist-Zilla-PluginBundle-Author-ETHER-0.072

          - fix syntax that parses badly on all perls before 5.21.1 - hey
            that's new enough for everyone, right?