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/GFrame.h

@@ -0,0 +1,32 @@
+#pragma once
+
+#include <LibGUI/GWidget.h>
+#include <SharedGraphics/StylePainter.h>
+
+class GFrame : public GWidget {
+public:
+    explicit GFrame(GWidget* parent = nullptr);
+    virtual ~GFrame() override;
+
+    int frame_thickness() const { return m_thickness; }
+    void set_frame_thickness(int thickness) { m_thickness = thickness; }
+
+    FrameShadow frame_shadow() const { return m_shadow; }
+    void set_frame_shadow(FrameShadow shadow) { m_shadow = shadow; }
+
+    FrameShape frame_shape() const { return m_shape; }
+    void set_frame_shape(FrameShape shape) { m_shape = shape; }
+
+    Rect frame_inner_rect_for_size(const Size& size) const { return { m_thickness, m_thickness, size.width() - m_thickness * 2, size.height() - m_thickness * 2 }; }
+    Rect frame_inner_rect() const { return frame_inner_rect_for_size(size()); }
+
+    virtual const char* class_name() const override { return "GFrame"; }
+
+protected:
+    void paint_event(GPaintEvent&) override;
+
+private:
+    int m_thickness { 0 };
+    FrameShadow m_shadow { FrameShadow::Plain };
+    FrameShape m_shape { FrameShape::NoFrame };
+};