move authentication_windows_client and mysql_clear_password clear client auth plugins

out of libmysql into separate dynamic plugins in the plugin/ directory.

move dialog and auth_socket plugins out of the plugin directory with examples into
dedicated directories in plugin/

plugin/auth_examples/clear_password_client.c

@@ -0,0 +1,47 @@
+/* Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+#include <mysql/client_plugin.h>
+#include <mysql.h>
+#include <string.h>
+
+/**
+  The main function of the mysql_clear_password authentication plugin.
+*/
+
+static int clear_password_auth_client(MYSQL_PLUGIN_VIO *vio, MYSQL *mysql)
+{
+  int res;
+
+  /* send password in clear text */
+  res= vio->write_packet(vio, (const unsigned char *) mysql->passwd, 
+                              strlen(mysql->passwd) + 1);
+
+  return res ? CR_ERROR : CR_OK;
+}
+
+mysql_declare_client_plugin(AUTHENTICATION)
+  "mysql_clear_password",
+  "Georgi Kodinov",
+  "Clear password authentication plugin",
+  {0,1,0},
+  "GPL",
+  NULL,
+  NULL,
+  NULL,
+  NULL,
+  clear_password_auth_client
+mysql_end_client_plugin;
+