Javascript Async tests

[Andrew Grumet]

We're running some tests of the Javascript client (lib/js/test/test.js) and
noticed that the Async tests ( module("Async") ) do not appear to be
running the supplied callbacks.   For example, in this block

  test("Double", function() {
    expect( 1 );

    QUnit.stop();
    client.testDouble(3.14159265, function(result) {
      equals(result, 3.14159265);
      QUnit.start();
    });
  });

the second argument to client.testDouble is not executed.  We can see the
network call and response, and the synchronous call to client.testDouble
passes.

Checking the generated client code, we don't see evidence of support for
this async mode.  Should it work?

Andrew