Add common headers to maxbase

To be included first in all headers. Defined and included common
ground and provides a place when one can affect all code.

maxutils/maxbase/include/maxbase/ccdefs.hh

@@ -0,0 +1,40 @@
+/*
+ * 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/bsl11.
+ *
+ * Change Date: 2020-01-01
+ *
+ * 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.
+ */
+
+#pragma once
+
+/**
+ * @file ccdefs.hh
+ *
+ * This file is to be included first by all C++ headers.
+ */
+
+#if !defined(__cplusplus)
+#error This file is only to be included by C++ code.
+#endif
+
+#include <maxbase/cdefs.h>
+#include <exception>
+#include <new>
+
+/**
+ * All classes of MaxBase are defined in the namespace @c maxbase.
+ */
+namespace maxbase
+{
+}
+
+/**
+ * Shorthand for the @c maxscale namespace.
+ */
+namespace mxb = maxbase;