Add skeleton hint router

The hint router will perform its scheduling solely based upon hints
provided by a filter (e.g. namedserverfilter) placed before it.

server/modules/routing/hintrouter/hintrouter.cc

@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2016 MariaDB Corporation Ab
+ *
+ * Use of this software is governed by the Business Source License included
+ * in the LICENSE.TXT file and at www.mariadb.com/bsl11.
+ *
+ * Change Date: 2019-07-01
+ *
+ * On the date above, in accordance with the Business Source License, use
+ * of this software will be governed by version 2 or later of the General
+ * Public License.
+ */
+
+#define MXS_MODULE_NAME "hintrouter"
+#include "hintrouter.hh"
+#include <maxscale/log_manager.h>
+
+
+HintRouter::HintRouter(SERVICE* pService)
+    : maxscale::Router<HintRouter, HintRouterSession>(pService)
+{
+    MXS_NOTICE("Hint router [%s] created.", pService->name);
+}
+
+
+//static
+HintRouter* HintRouter::create(SERVICE* pService, char** pzOptions)
+{
+    return new HintRouter(pService);
+}
+
+
+HintRouterSession* HintRouter::newSession(MXS_SESSION *pSession)
+{
+    return new HintRouterSession(pSession, this);
+}
+
+void HintRouter::diagnostics(DCB* pOut)
+{
+}
+
+uint64_t HintRouter::getCapabilities()
+{
+    return 0;
+}
+
+
+extern "C" MXS_MODULE* MXS_CREATE_MODULE()
+{
+    static MXS_MODULE module =
+    {
+        MXS_MODULE_API_ROUTER,   /* Module type */
+        MXS_MODULE_BETA_RELEASE, /* Release status */
+        MXS_ROUTER_VERSION,      /* Implemented module API version */
+        "A hint router", /* Description */
+        "V1.0.0", /* Module version */
+        &HintRouter::s_object,
+        NULL, /* Process init, can be null */
+        NULL, /* Process finish, can be null */
+        NULL, /* Thread init */
+        NULL, /* Thread finish */
+        {
+            {MXS_END_MODULE_PARAMS}
+        }
+    };
+
+    return &module;
+}