CtrlCore: IsAvailableImage, IsClipboardAvailableImage, removed obsolete Palette code in win32

upptst/IsClipboardAvailable/IsClipboardAvailable.upp

@@ -0,0 +1,9 @@
+uses
+	CtrlLib;
+
+file
+	main.cpp;
+
+mainconfig
+	"" = "GUI";
+

upptst/IsClipboardAvailable/main.cpp

@@ -0,0 +1,26 @@
+#include <CtrlLib/CtrlLib.h>
+
+using namespace Upp;
+
+struct MyApp : TopWindow {
+	TimeCallback tm;
+	
+	void Paint(Draw& w) override {
+		w.DrawRect(GetSize(), SColorPaper());
+		if(IsClipboardAvailableImage())
+			w.DrawText(0, 0, "IMAGE");
+		if(IsClipboardAvailableText())
+			w.DrawText(0, 50, "TEXT");
+		if(IsAvailableFiles(Ctrl::Clipboard()))
+			w.DrawText(0, 100, "FILES");
+	}
+	
+	MyApp() {
+		tm.Set(-200, [=] { Refresh(); });
+	}
+};
+
+GUI_APP_MAIN
+{
+	MyApp().Run();
+}