Introduced in 2.0 beta 8, 2006 A.D. Went absolutely untouched in 8 years
of refactoring, when Python 2.5 and PostgreSQL 8.1 roamed the earth.

I would say it has stood the test of the time.

These functions don't need to exist: exposing the type in the module is
enough. It is actually better as one may use isinstance and such.

The default repr is enough: it prints <TypeName at 0xADDR> instead of
<TypeName object at 0xADDR>.

The only people being hurt by this change are the ones using doctests:
they deserve it.

Non-containers don't need GC. It was half-baked anyway
as the tp_clear was often not set. Dropped tp_traverse too
for these objects as unused.

The defaut is already to call PyObject_GC_Del.

The getquoted methods always return bytes. The str() convert this
representation to string on the fly.

Just compiled! No test run yet and many points to review, marked in the
code.

The patch is largely Martin von Löwis work, simplified after refactoring
in the previous commits and adapted to the new code (as the patch was
originally for Psycopg 2.0.9)

stringobject is not to be imported with Python 3.