Improved new Py_TRACE_REFS gimmicks.

Improved new Py_TRACE_REFS gimmicks.
Arranged that all the objects exposed by __builtin__ appear in the list
of all objects.  I basically peed away two days tracking down a mystery
leak in sys.gettotalrefcount() in a ZODB app (== tons of code), because
the object leaking the references didn't appear in the sys.getobjects(0)
list.  The object happened to be False.  Now False is in the list, along
with other popular & previously missing leak candidates (like None).
Alas, we still don't have a choke point covering *all* Python objects,
so the list of all objects may still be incomplete.