[issue1682] Move Demo/classes/Rat.py to Lib/fractions.py and fix it up.

[Mark Dickinson]

Mark Dickinson added the comment:

And here's the diff for math.gcd.  It's not production quality---it's just 
there to show what's possible.

Added file: http://bugs.python.org/file9486/lehmer_gcd.patch

__________________________________
Tracker <report at bugs.python.org>
<http://bugs.python.org/issue1682>
__________________________________