PyErr_Format() these new C API methods can be used instead of
    sprintf()'s into hardcoded char* buffers.  This allows us to fix
    many situation where long package, module, or class names get
    truncated in reprs.

    PyString_FromFormat() is the varargs variety.
    PyString_FromFormatV() is the va_list variety

    Original PyErr_Format() code was modified to allow %p and %ld
    expansions.

    Many reprs were converted to this, checkins coming soo.  Not
    changed: complex_repr(), float_repr(), float_print(), float_str(),
    int_repr().  There may be other candidates not yet converted.

    Closes patch #454743.