fix for filepath to string conversions

src/render.cpp

@@ -6,7 +6,6 @@
 #include <fstream>
 
 #ifdef _WIN32
-  #include "util.h"
   #define POPEN _popen
   #define PCLOSE _pclose
   #define PWRITE_MODE "wb"
@@ -19,7 +18,9 @@
 #endif
 
 #include "log.h"
+#include "string_.h"
 
+using namespace anm2ed::util;
 using namespace anm2ed::resource;
 using namespace glm;