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/main.cpp

@@ -0,0 +1,23 @@
+#include "Client.h"
+#include <LibCore/EventLoop.h>
+#include <LibCore/TCPServer.h>
+
+int main(int argc, char** argv)
+{
+    (void)argc;
+    (void)argv;
+
+    Core::EventLoop loop;
+
+    auto server = Core::TCPServer::construct();
+
+    server->on_ready_to_accept = [&] {
+        auto client_socket = server->accept();
+        ASSERT(client_socket);
+        auto client = WebServer::Client::construct(client_socket.release_nonnull(), server);
+        client->start();
+    };
+
+    server->listen({}, 8000);
+    return loop.exec();
+}