LibDraw: Introduce (formerly known as SharedGraphics.)

Instead of LibGUI and WindowServer building their own copies of the drawing
and graphics code, let's it in a separate LibDraw library.

This avoids building the code twice, and will encourage better separation
of concerns. :^)

Libraries/LibDraw/install.sh

@@ -0,0 +1,4 @@
+#!/bin/bash
+
+mkdir -p ../Root/usr/include/LibGfx/
+cp *.h ../Root/usr/include/LibGfx/