Libraries: Create top level directory for libraries.

Things were getting a little crowded in the project root, so this patch
moves the Lib*/ directories into Libraries/.

Libraries/LibGUI/GMenuItem.h

@@ -0,0 +1,49 @@
+#pragma once
+
+#include <AK/AKString.h>
+#include <AK/Badge.h>
+
+class GAction;
+class GMenu;
+
+class GMenuItem {
+public:
+    enum Type {
+        Invalid,
+        Action,
+        Separator
+    };
+
+    GMenuItem(unsigned menu_id, Type);
+    GMenuItem(unsigned menu_id, NonnullRefPtr<GAction>&&);
+    ~GMenuItem();
+
+    Type type() const { return m_type; }
+    String text() const;
+    const GAction* action() const { return m_action.ptr(); }
+    GAction* action() { return m_action.ptr(); }
+    unsigned identifier() const { return m_identifier; }
+
+    bool is_checkable() const { return m_checkable; }
+    void set_checkable(bool checkable) { m_checkable = checkable; }
+
+    bool is_checked() const { return m_checked; }
+    void set_checked(bool);
+
+    bool is_enabled() const { return m_enabled; }
+    void set_enabled(bool);
+
+    void set_menu_id(Badge<GMenu>, unsigned menu_id) { m_menu_id = menu_id; }
+    void set_identifier(Badge<GMenu>, unsigned identifier) { m_identifier = identifier; }
+
+private:
+    void update_window_server();
+
+    Type m_type { Invalid };
+    int m_menu_id { -1 };
+    unsigned m_identifier { 0 };
+    bool m_enabled { true };
+    bool m_checkable { false };
+    bool m_checked { false };
+    RefPtr<GAction> m_action;
+};