renaming
a utility ``clone" function

This functions uses a JSON trick to clone a java script object.  It is usefull
for some tests, when you want to pass something to the code, and want to pass
it ``by value" and not ``by reference".
rewrote the async ajax testing

A new class AjaxTest handles this task. Hopefully this will result in
more readable tests.
small refactoring
verbose scenario: to aid debugging

The Scenario class now has an optional ``verbose" mode, in which it
prints explicitly every call it examines. This may add debugging when
one is not sure what the state of the scenario is.