From Pjotr Svetachov, previous obj "commit broke compilation under visual studio 2013. To use std::not1 you need to include the functional header. Here is a fix."

src/osgPlugins/obj/obj.cpp

@@ -16,6 +16,7 @@
 #include <fstream>
 #include <string>
 #include <stdio.h>
+#include <functional>
 
 #include "obj.h"