Refactoring louloulibs and cmake

Use OBJECT libraries
Remove the louloulibs directory
Write FOUND variables in the cache

src/network/dns_socket_handler.hpp

@@ -0,0 +1,33 @@
+#pragma once
+
+#include <biboumi.h>
+#ifdef UDNS_FOUND
+
+#include <network/socket_handler.hpp>
+
+/**
+ * Manage the UDP socket provided by udns, we do not create, open or close the
+ * socket ourself: this is done by udns.  We only watch it for readability
+ */
+class DNSSocketHandler: public SocketHandler
+{
+public:
+  explicit DNSSocketHandler(std::shared_ptr<Poller>& poller, const socket_t socket);
+  ~DNSSocketHandler();
+  DNSSocketHandler(const DNSSocketHandler&) = delete;
+  DNSSocketHandler(DNSSocketHandler&&) = delete;
+  DNSSocketHandler& operator=(const DNSSocketHandler&) = delete;
+  DNSSocketHandler& operator=(DNSSocketHandler&&) = delete;
+
+  void on_recv() override final;
+
+  /**
+   * Always true, see the comment for connect()
+   */
+  bool is_connected() const override final;
+
+  void watch();
+  void unwatch();
+};
+
+#endif // UDNS_FOUND