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/auroramon/auroramon.c

@@ -15,6 +15,8 @@
  * @file auroramon.c - Amazon RDS Aurora monitor
  */
 
+#define MXS_MODULE_NAME "auroramon"
+
 #include <maxscale/modinfo.h>
 #include <maxscale/thread.h>
 #include <maxscale/monitor.h>