Include <algorithm> when std::min/max is used.

It won't build in Visual Studio 2013 unless we do this.

src/common/runtime.cpp

@@ -29,6 +29,7 @@
 #include <thread/threads.h>
 
 // C++
+#include <algorithm>
 #include <iostream>
 #include <cstdio>
 

src/modules/graphics/opengl/ParticleSystem.cpp

@@ -27,6 +27,7 @@
 #include "OpenGL.h"
 
 // STD
+#include <algorithm>
 #include <cmath>
 #include <cstdlib>