Change towards getting STB working on shared

Source/Tools/RampGenerator/RampGenerator.cpp

@@ -28,6 +28,10 @@
 #include <windows.h>
 #endif
 
+
+#define STB_IMAGE_IMPLEMENTATION
+#define STB_IMAGE_WRITE_IMPLEMENTATION
+#include <STB/stb_image.h>
 #include <STB/stb_image_write.h>
 
 #include <Urho3D/DebugNew.h>