[Python-checkins] cpython (3.2): Add links to make the math docs more usable.

[Terry Reedy]

>> +   Return the `Gamma function<http://en.wikipedia.org/wiki/Gamma_function>` at *x*.
>>
>
> There's a space missing here, and the link doesn't work.

It does for me. This may depend on the mail reader and whether it parses 
the url out in spite of the missing space.