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/GIcon.h

@@ -0,0 +1,43 @@
+#pragma once
+
+#include <AK/HashMap.h>
+#include <SharedGraphics/GraphicsBitmap.h>
+
+class GIconImpl : public RefCounted<GIconImpl> {
+public:
+    static NonnullRefPtr<GIconImpl> create() { return adopt(*new GIconImpl); }
+    ~GIconImpl() {}
+
+    const GraphicsBitmap* bitmap_for_size(int) const;
+    void set_bitmap_for_size(int, RefPtr<GraphicsBitmap>&&);
+
+private:
+    GIconImpl() {}
+    HashMap<int, RefPtr<GraphicsBitmap>> m_bitmaps;
+};
+
+class GIcon {
+public:
+    GIcon();
+    explicit GIcon(RefPtr<GraphicsBitmap>&&);
+    explicit GIcon(RefPtr<GraphicsBitmap>&&, RefPtr<GraphicsBitmap>&&);
+    explicit GIcon(const GIconImpl&);
+    GIcon(const GIcon&);
+    ~GIcon() {}
+
+    static GIcon default_icon(const StringView&);
+
+    GIcon& operator=(const GIcon& other)
+    {
+        m_impl = other.m_impl.copy_ref();
+        return *this;
+    }
+
+    const GraphicsBitmap* bitmap_for_size(int size) const { return m_impl->bitmap_for_size(size); }
+    void set_bitmap_for_size(int size, RefPtr<GraphicsBitmap>&& bitmap) { m_impl->set_bitmap_for_size(size, move(bitmap)); }
+
+    const GIconImpl& impl() const { return *m_impl; }
+
+private:
+    NonnullRefPtr<GIconImpl> m_impl;
+};