martine/ninja — pull request #397 by nico (2012-08-05 19:04:16+00:00)
Title: Include unistd.h in files that use unlink() on OS X.

`man unlink` says this is necessary, and according to a report by
Claus Klein, omitting them breaks the build on OS X 10.5 with gcc 4.7.

(On Windows, ninja's util.h includes a define for unlink.)