nicer icns on win64

Fltk/FlGui.cpp

@@ -40,7 +40,7 @@ typedef unsigned long intptr_t;
 #include "Plugin.h"
 #include "PluginManager.h"
 #include "OpenFile.h"
-#include "Win32Icon.h"
+#include "WinIcon.h"
 #include "Options.h"
 #include "CommandLine.h"
 #include "Context.h"

Fltk/Win32Icon.rc

 
-#include "Win32Icon.h"
+#include "WinIcon.h"
 
 IDI_ICON   ICON    DISCARDABLE     "Win32Icon.ico"
 

Fltk/Win64Icon.rc

+
+#include "WinIcon.h"
+
+IDI_ICON   ICON    DISCARDABLE     "Win64Icon.ico"
+