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/monitor/galeramon/galeramon.c

@@ -33,6 +33,7 @@
  * @endverbatim
  */
 
+#define MXS_MODULE_NAME "galeramon"
 
 #include "galeramon.h"
 #include <maxscale/dcb.h>