The attached patch removes the PyCore_* memory
management layer and gives up on the hope that
PyObject_DEL() will ever be anything but free().

pymalloc is given a visible API in the form of
PyMalloc_Malloc, PyMalloc_Realloc, PyMalloc_Free.  
A new object memory interface is implemented
on top of pymalloc in the form of
PyMalloc_{New,NewVar,Del}.  Those are ugly names.
Please suggest alternatives.

Some objects are changed to use pymalloc.  The
GC memory functions are changed to use pymalloc.

The configure support for enabling pymalloc was 
also removed.  Perhaps that should be left in so
people can disable pymalloc on low memory machines.

I left typeobject using the system allocator (new style
classes will not use pymalloc).  Fixing that is
probably a job for Guido.