[Patches] introducing math.rint

[Tim Peters]

[Guido, about rint]
> Not to worry, I've already added the necessary magic to the configure
> script.

Are you sure you want to?  While I expect that the existence of some
functions in the OS module depends on the platform, I'm really dubious about
extending that to other modules, and it's especially dubious in a module
like math.  I learned today that Windows doesn't support "rint" either --
this is a function that apparently exists (at least under that name) only on
some unknown subset of Unix derivatives.

> (PS Tim, did you get a chance to look at the second installment of the
> cmarh.acosh/asinh patches?)

No, it's way back in my inbox, and I don't expect to get to it this month.
However, if I had the hours it would take to look at this carefully, I would
probably conclude that all the complex transcendentals suffer deep numeric
problems (the ones I looked at so far are certainly fragile as eggshells!).
On that basis, if the new patch isn't obviously broken, it's probably no
worse than what it's replacing, and at least one motivated user thinks it's
a lot better <0.5 wink>.