solve error with min/max macro for windows

apps/openmw/mwgui/class.cpp

@@ -10,6 +10,9 @@
 #include <boost/algorithm/string.hpp>
 #include <boost/lexical_cast.hpp>
 
+#undef min
+#undef max
+
 using namespace MWGui;
 
 /* GenerateClassResultDialog */

apps/openmw/mwgui/review.cpp

@@ -10,6 +10,9 @@
 
 #include <cmath>
 
+#undef min
+#undef max
+
 using namespace MWGui;
 using namespace Widgets;