[docs] platform.python_implementation() miswording

[Corey Richardson]

(http://docs.python.org/library/platform.html#platform.python_implementation)

>    Returns a string identifying the Python implementation. Possible
>    return values are: ‘CPython’, ‘IronPython’, ‘Jython’, ‘PyPy’.

Should read:

Returns a string identifying the Python implementation. Some potential
return values are: ‘Python’, ‘IronPython’, ‘Jython’, 'PyPy’.

-- 
Corey Richardson