More hacking on Widgets.

Widgets/WindowManager.h

@@ -0,0 +1,24 @@
+#pragma once
+
+class Widget;
+
+#include "Object.h"
+#include <AK/HashTable.h>
+
+class WindowManager : public Object {
+public:
+    static WindowManager& the();
+
+    void addWindow(Widget&);
+    void paintWindowFrames();
+
+    void notifyTitleChanged(Widget&);
+
+private:
+    WindowManager();
+    ~WindowManager();
+
+    void paintWindowFrame(Widget&);
+
+    HashTable<Widget*> m_windows;
+};