Move headers from server/include to include/maxscale

- Headers now to be included as <maxscale/xyz.h>
- First step, no cleanup of headers has been made. Only moving
  from one place to another + necessary modifications.

include/maxscale/adminusers.h.in

@@ -0,0 +1,66 @@
+#ifndef _ADMINUSERS_H
+#define _ADMINUSERS_H
+/*
+ * 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/bsl.
+ *
+ * Change Date: 2019-07-01
+ *
+ * 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.
+ */
+
+/**
+ * @file adminusers.h - Administration users support routines
+ *
+ * @verbatim
+ * Revision History
+ *
+ * Date         Who             Description
+ * 18/07/13     Mark Riddoch    Initial implementation
+ *
+ * @endverbatim
+ */
+#include <maxscale/dcb.h>
+
+#define ADMIN_SALT "$1$MXS"
+
+/* Max length of fields in for admin users */
+#define ADMIN_USER_MAXLEN       128
+#define ADMIN_PASSWORD_MAXLEN   128
+
+/** Default user for the administrative interface */
+#define DEFAULT_ADMIN_USER "@DEFAULT_ADMIN_USER@"
+
+/*
+ * MySQL session specific data
+ *
+ */
+typedef struct admin_session
+{
+#if defined(SS_DEBUG)
+    skygw_chk_t adminses_chk_top;
+#endif
+    char user[ADMIN_USER_MAXLEN + 1];               /*< username       */
+    bool validated;                                 /* Was user validated? */
+#if defined(SS_DEBUG)
+    skygw_chk_t adminses_chk_tail;
+#endif
+} ADMIN_session;
+
+extern const char *admin_enable_linux_account(const char *uname);
+extern const char *admin_disable_linux_account(const char *uname);
+extern bool        admin_linux_account_enabled(const char *uname);
+
+extern const char *admin_add_inet_user(const char *uname, const char *password);
+extern const char *admin_remove_inet_user(const char *uname, const char *password);
+extern bool        admin_inet_user_exists(const char *uname);
+
+extern bool        admin_verify_inet_user(const char *uname, const char *password);
+
+extern void        dcb_PrintAdminUsers(DCB *dcb);
+
+#endif