Date objects equality assertion

[jacky163com]

version 2.2, in jsUnitCore.js, assertObjectEquals(date1, date2) failed to compare two equivalent Date objects.

The cause is in the same file,
JsUnit.PRIMITIVE_EQUALITY_PREDICATES

A quick solution follows.

1. Add the following:
   JsUnit.DATE_EQUALITY_PREDICATE = function(var1, var2) {
   return var1.valueOf() === var2.valueOf();
   };
2. Modify the following line
   'Date': JsUnit.TRIPLE_EQUALITY_PREDICATE,
   to the following line
   'Date': JsUnit.DATE_EQUALITY_PREDICATE,

Please review the solution.