more tests and fix tests to be same as Date::Calc, which is same as ISO8601
more tests and fix tests to be same as Date::Calc, which is same as ISO8601

1nickt/DateTime.pm,chansen/DateTime.pm,autarch/DateTime.pm,chansen/DateTime.pm,1nickt/DateTime.pm,chansen/DateTime.pm,autarch/DateTime.pm,1nickt/DateTime.pm