Fix compile error with VS 2013

[ethan-tqa]

According to this http://msdn.microsoft.com/en-us/library/vstudio/bb531344(v=vs.120).aspx, must be included to use std::min() and std::max()

[dougbinks]

Thanks, that's a good find.

I'll be adding VS 2013 to my test suite when it's officially released, so should hopefully catch these issues in future.

Note that algorithm can be included on all platforms for std::min and std::max, so I'll likely move to removing the #if once I get the chance to test this change on those platforms. For now I'll pull this.

[ethan-tqa]

It is unlikely that VS 2013 will be released in the next few months, so I think you can actually grab VS 2013 Preview to test.

[dougbinks]

I don't have a spare system or image ready to install VS Preview on, and from previous experience I know installing to my main system can mean a full re-install later, so I'll pass on the preview.