BuildSystem: Cleanup userspace directory layout

userspace programs are now in userspace/programs
userspace tests are now in userspace/tests

This makes listing userspace projects much cleaner. Libraries were
already separated to their own directory, so other programs should also.

userspace/programs/WindowServer/WindowServer.h

@@ -0,0 +1,64 @@
+#pragma once
+
+#include "Framebuffer.h"
+#include "Window.h"
+
+#include <BAN/Function.h>
+#include <BAN/Iteration.h>
+#include <BAN/Vector.h>
+#include <BAN/HashMap.h>
+
+#include <LibFont/Font.h>
+#include <LibGUI/Window.h>
+#include <LibImage/Image.h>
+#include <LibInput/KeyEvent.h>
+#include <LibInput/MouseEvent.h>
+
+#include <sys/select.h>
+
+class WindowServer
+{
+public:
+	WindowServer(Framebuffer& framebuffer);
+
+	BAN::ErrorOr<void> set_background_image(BAN::UniqPtr<LibImage::Image>);
+
+	void on_window_packet(int fd, LibGUI::WindowPacket);
+
+	void on_key_event(LibInput::KeyEvent event);
+	void on_mouse_button(LibInput::MouseButtonEvent event);
+	void on_mouse_move(LibInput::MouseMoveEvent event);
+	void on_mouse_scroll(LibInput::MouseScrollEvent event);
+
+	void set_focused_window(BAN::RefPtr<Window> window);
+	void invalidate(Rectangle area);
+	void sync();
+
+	Rectangle cursor_area() const;
+
+	void add_client_fd(int fd);
+	void remove_client_fd(int fd);
+	int get_client_fds(fd_set& fds) const;
+	void for_each_client_fd(const BAN::Function<BAN::Iteration(int)>& callback);
+
+	bool is_stopped() const { return m_is_stopped; }
+
+private:
+	Framebuffer& m_framebuffer;
+	BAN::Vector<BAN::RefPtr<Window>> m_client_windows;
+	BAN::Vector<int> m_client_fds;
+
+	BAN::Vector<uint8_t> m_pages_to_sync_bitmap;
+
+	BAN::UniqPtr<LibImage::Image> m_background_image;
+
+	bool m_is_mod_key_held { false };
+	bool m_is_moving_window { false };
+	BAN::RefPtr<Window> m_focused_window;
+	Position m_cursor;
+
+	bool m_deleted_window { false };
+	bool m_is_stopped { false };
+
+	LibFont::Font m_font;
+};