Check for nil and unsupported types and return nil as the comparison result just like Date class does.
This works in the same way as Ruby implementation (compares astronomical julian days as rational numbers), but it's just 5.5x faster. One known regression: it's no longer possible to compare Date with Fixnum.
…nts. For example, Date.civil(2008, 7, -1) will construct "2008-7-31" date.
…and causing a NULL pointer error when strftime had to pass down to the original method
…r subversion era changes