Add definitions of MXS_MODULE_NAME to all modules

All modules now declare a name for the module. This is name is added as a
prefix to all messages logged by a module. The prefix should help
determine which part of the system logs a message.

server/modules/protocol/CDC/cdc.c

@@ -30,6 +30,8 @@
  * @endverbatim
  */
 
+#define MXS_MODULE_NAME "CDC"
+
 #include <cdc.h>
 #include <maxscale/alloc.h>
 #include <maxscale/modinfo.h>

server/modules/protocol/HTTPD/httpd.c

@@ -32,6 +32,8 @@
  * @endverbatim
  */
 
+#define MXS_MODULE_NAME "HTTPD"
+
 #include "httpd.h"
 #include <ctype.h>
 #include <maxscale/alloc.h>

server/modules/protocol/MySQL/MySQLBackend/mysql_backend.c

@@ -11,6 +11,8 @@
  * Public License.
  */
 
+#define MXS_MODULE_NAME "MySQLBackend"
+
 #include <maxscale/protocol/mysql.h>
 #include <maxscale/log_manager.h>
 #include <maxscale/modutil.h>

server/modules/protocol/MySQL/MySQLClient/mysql_client.c

@@ -45,6 +45,9 @@
  * 07/02/2016   Martin Brampton         Split off authentication and SSL.
  * 31/05/2016   Martin Brampton         Implement connection throttling
  */
+
+#define MXS_MODULE_NAME "MySQLClient"
+
 #include <maxscale/protocol.h>
 #include <maxscale/alloc.h>
 #include <maxscale/log_manager.h>

server/modules/protocol/maxscaled/maxscaled.c

@@ -10,6 +10,9 @@
  * of this software will be governed by version 2 or later of the General
  * Public License.
  */
+
+#define MXS_MODULE_NAME "maxscaled"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>

server/modules/protocol/telnetd/telnetd.c

@@ -10,6 +10,9 @@
  * of this software will be governed by version 2 or later of the General
  * Public License.
  */
+
+#define MXS_MODULE_NAME "telnetd"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>