Added stub module for repr.

If configparser is unavailable, try to import configparser using its
old name. This is required for backward-compatibility with older
Python versions.

The distutils module should continue to use the old ConfigParser name,
for backward-compatibility.

not appear to be a new bug, its just that the test coverage went up
recently exposing it.  (I verified that by testing this test code on
an older Modules/_bsddb.c)