Could you also update documentation in Doc/distutils/apiref.rst?

Also, test_strtobool in Lib/distutils/tests/test_util.py doesn't test the following case:

    >>> from distutils.util import strtobool
    >>> strtobool('x')
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
      File "/home/berker/projects/cpython/default/Lib/distutils/util.py", line 317, in strtobool
        raise ValueError("invalid truth value %r" % (val,)) 
    ValueError: invalid truth value 'x'

Bonus points if you add a test for that :)

Thanks!