[phobos] Proposed changes to std.math + introduce std.mathspecial

[Lars Tandle Kyllingstad]

On Thu, 2010-11-18 at 12:06 +0100, Lars Tandle Kyllingstad wrote:
> On Wed, 2010-11-17 at 22:09 +0100, Don Clugston wrote:
> 
> > (2) Delete etc.gamma
> 
> I didn't even know this module existed.  I recently implemented the
> gamma function myself, based on the same source (Cephes).  If I'd known
> about this it would have saved me quite a bit of time, so I say yes,
> let's bring it out of hiding.

Well, how about that -- it seems I would have saved even more time by
realising that there is a tgamma() function in std.math already... :p
(It seems to be slightly less accurate than the Cephes one, though, as
it doesn't pass the unittests I wrote for my implementation.)

-Lars