MXS-1775 Cleanup monitor class headers

- All classes now declared in separate header file
- Header files have .hh-suffix

server/modules/monitor/ndbclustermon/ndbclustermon.cc

@@ -17,7 +17,7 @@
 
 #define MXS_MODULE_NAME "ndbclustermon"
 
-#include "ndbclustermon.h"
+#include "ndbclustermon.hh"
 #include <maxscale/alloc.h>
 #include <maxscale/mysql_utils.h>
 

server/modules/monitor/ndbclustermon/ndbclustermon.hh

@@ -1,5 +1,4 @@
 #pragma once
-
 /*
  * Copyright (c) 2016 MariaDB Corporation Ab
  *
@@ -13,11 +12,14 @@
  * Public License.
  */
 
+#include <maxscale/cppdefs.hh>
 #include <maxscale/monitor.hh>
-#include <maxscale/spinlock.h>
 #include <maxscale/thread.h>
 
-// The handle for an instance of a NDB Cluster Monitor module
+/**
+ * @file ndbcclustermon.hh A NDBC cluster monitor
+ */
+
 class NDBCMonitor : public MXS_MONITOR_INSTANCE
 {
 public: