_sort() doesn't work with coerced Types

(Bug, Closed -> Fixed, Priority: Critical, Test Status: Unit tested , Reported By Justin du Coeur, )
Functions
Summary: That is, if I have a List of mixed Types, where they Types can be coerced to match, they don't sort together properly.
Found this while unit-testing I should be able to mix Dates and DateTimes -- it turned out that, even though I could now mix Dates and DateTimes, they still didn't sort correctly. The problem was that, deep in its heart, _sort() was written to assume exact Type matches: it wasn't using coercion, even if that was legal.