Use the site python module to find out where the install directory is

    * Makefile.in: Regenerated
    * configure: Regenerated
    * configure.ac: Create a PYTHON_PACKAGES variable describing where
        the packages should be put
    * doc/Makefile.in: Regenerated
    * gcc_plugin/Makefile.in: Regenerated
    * include/Makefile.in: Regenerated
    * mageec/Makefile.am: Use the new PYTHON_PACKAGES variable as the
        symlink destination for the module
    * mageec/Makefile.in: Regenerated
    * ml/C5/Makefile.in: Regenerated
    * ml/Makefile.in: Regenerated
    * testsuite/Makefile.in: Regenerated
    * testsuite/gcc_plugin.tests/Makefile.in: Regenerated
    * testsuite/mageec.tests/Makefile.in: Regenerated
    * testsuite/python.tests/Makefile.in: Regenerated