Alexa version of sort with NlogM merge

[Lars Clausen]

Hi!

We got a copy of a derivation of the GNU sort(3) program from Alexa.
They've done some improvements to handle large collections of files
better, it seems, and use a specialized qsort.  But most interestingly,
they have a merging algorithm that's O(N*log(M)) rather than O(N*M),
where N is the number of lines output, and M is the number of input
files.  You may want to consider that part for addition to future
versions of sort().

I'm attaching the source (too much has been specialized for diff to be
useful), which includes the standard GNU header.  If you want to contact
the author before looking at the source, it's address@hidden  Hope this
is useful.

-Lars