Add missing license blurbs

Some file were missing the license blurb at the top of the file.

server/include/hk_heartbeat.h

@@ -1,6 +1,19 @@
 #ifndef _HK_HEARTBEAT_H
 #define _HK_HEARTBEAT_H
 
+/*
+ * 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/bsl.
+ *
+ * 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.
+ */
+
 /**
  * The global housekeeper heartbeat value. This value is incremented
  * every 100 milliseconds and may be used for crude timing etc.

server/include/test_utils.h

@@ -1,5 +1,19 @@
 #ifndef TEST_UTILS_H
 #define TEST_UTILS_H
+
+/*
+ * 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/bsl.
+ *
+ * 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.
+ */
+
 #include <maxscale/poll.h>
 #include <dcb.h>
 #include <housekeeper.h>

server/modules/include/avrorouter.h

@@ -1,3 +1,16 @@
+/*
+ * 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/bsl.
+ *
+ * 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.
+ */
+
 /**
  * MaxScale AVRO router
  *

server/modules/include/rwsplit_internal.h

@@ -1,7 +1,14 @@
 /*
- * To change this license header, choose License Headers in Project Properties.
- * To change this template file, choose Tools | Templates
- * and open the template in the editor.
+ * 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/bsl.
+ *
+ * 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.
  */
 
 /* 

server/modules/include/sharding_common.h

@@ -1,3 +1,16 @@
+/*
+ * 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/bsl.
+ *
+ * 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.
+ */
+
 #ifndef _SHARDING_COMMON_HG
 #define _SHARDING_COMMON_HG
 

server/test/maxscale_test.h.in

@@ -1,5 +1,19 @@
 #ifndef MAXSCALE_TEST_H
 #define MAXSCALE_TEST_H
+
+/*
+ * 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/bsl.
+ *
+ * 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 TEST_DIR "@CMAKE_BINARY_DIR@"
 #define TEST_LOG_DIR "@CMAKE_BINARY_DIR@/log"
 #define TEST_BIN_DIR "@CMAKE_BINARY_DIR@/bin"