Improve detection of Python 3.2 installations

Improve detection of Python 3.2 installations

Because of ABI tagging, the library version number might no longer be
exactly the Python version number, so do extra lookups.  This affects
installations without a shared library, such as ActiveState's
installer.

Also update the way to detect the location of the 'config' directory,
which can also be versioned.

Ashesh Vashi