Itseez/opencv — pull request #1572 by emchristiansen (2013-10-05 22:55:12+00:00)
Title: Adds "#include <limits>" to fix build

I needed to add this include to make OpenCV build on my Ubuntu 13.10 machine and my Travis CI instance.

I think some versions of g++ may include this by default, but not all.
Thus, an explicit include is required.