libroot: added ability to communicate with the launch_daemon.

* These methods don't really work yet, as BMessage doesn't support
  replying with a KMessage; the request is received, but the reply
  never gets to the target.

headers/private/libroot/launch.h

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2015, Axel Dörfler, [email protected].
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef _LIBROOT_LAUNCH_H
+#define _LIBROOT_LAUNCH_H
+
+
+#include <LaunchDaemonDefs.h>
+#include <OS.h>
+
+
+#ifdef __cplusplus
+namespace BPrivate {
+
+
+class KMessage;
+
+
+port_id		get_launch_daemon_port();
+status_t	send_request_to_launch_daemon(KMessage& request, KMessage& reply);
+status_t	get_launch_data(const char* signature, KMessage& data);
+
+
+}	// namespace BPrivate
+#endif	// __cplusplus
+
+
+#endif	// _LIBROOT_LAUNCH_H