Remove std.algorithm.completeSort.

[Andrei Alexandrescu]

On 7/2/12 5:50 AM, Bernard Helyer wrote:
> Because it's apparent to me it's not going to be fixed. Furthermore,
> what does it gain you over sort(chain(a, b))? This is the first time in
> the 2 years it's been broken (and apparently Jesse is the only one that
> knew this! :D) someone has come to IRC with a problem regarding it. From
> that highly biased sample, I conclude it's not getting used. Anywhere.
> Or that bug would have more noise (it's the only result for
> 'completeSort' on bugzilla).
>
> http://d.puremagic.com/issues/show_bug.cgi?id=4936

It's a fairly specialized function, but we shouldn't draw conclusions 
about usefulness of library functions from current use alone.

Andrei