Accidentally removed the following message from Victor Stinner;  
apologies.  (Time to turn off tap-to-click on my trackpad, methinks.)

> See also issue #3724 which proposes to support long integers for 
> math.log2().

One other note:  in Fredrik's patch there's commented out code for a 
numbits *property* (rather than a method).  Is there any good reason to 
make this a property?  I don't have a good feeling for when something 
should be a method and when it should be a property, but in this case 
I'd be inclined to leave numbits as a method.

Are there general guidelines for making things properties?