WebServer: Implement a very basic HTTP server :^)

This server listens on port 8000 and serves HTML files from /www.
It's very simple and quite naive, but I think we can start here and
build our way to something pretty neat.

Work towards #792.

Servers/WebServer/Client.h

@@ -0,0 +1,28 @@
+#pragma once
+
+#include <LibCore/Object.h>
+#include <LibCore/TCPSocket.h>
+
+namespace Core {
+class HttpRequest;
+}
+
+namespace WebServer {
+
+class Client final : public Core::Object {
+    C_OBJECT(Client);
+public:
+    void start();
+
+private:
+    Client(NonnullRefPtr<Core::TCPSocket>, Core::Object* parent);
+
+    void handle_request(ByteBuffer);
+    void send_error_response(unsigned code, const StringView& message, const Core::HttpRequest&);
+    void die();
+    void log_response(unsigned code, const Core::HttpRequest&);
+
+    NonnullRefPtr<Core::TCPSocket> m_socket;
+};
+
+}