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/

include/mysql/auth_dialog_client.h

@@ -0,0 +1,56 @@
+#ifndef MYSQL_AUTH_DIALOG_CLIENT_INCLUDED
+/* Copyright (C) 2010 Sergei Golubchik and Monty Program Ab
+
+   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 */
+
+/**
+  @file
+
+  Definitions needed to use Dialog client authentication plugin
+*/
+
+struct st_mysql;
+
+#define MYSQL_AUTH_DIALOG_CLIENT_INCLUDED
+
+/**
+  type of the mysql_authentication_dialog_ask function
+
+  @param mysql          mysql
+  @param type           type of the input
+                        1 - ordinary string input
+                        2 - password string
+  @param prompt         prompt
+  @param buf            a buffer to store the use input
+  @param buf_len        the length of the buffer
+
+  @retval               a pointer to the user input string.
+                        It may be equal to 'buf' or to 'mysql->password'.
+                        In all other cases it is assumed to be an allocated
+                        string, and the "dialog" plugin will free() it.
+*/
+typedef char *(*mysql_authentication_dialog_ask_t)(struct st_mysql *mysql,
+                      int type, const char *prompt, char *buf, int buf_len);
+
+/**
+  first byte of the question string is the question "type".
+  It can be an "ordinary" or a "password" question.
+  The last bit set marks a last question in the authentication exchange.
+*/
+#define ORDINARY_QUESTION       "\2"
+#define LAST_QUESTION           "\3"
+#define PASSWORD_QUESTION       "\4"
+#define LAST_PASSWORD           "\5"
+
+#endif

include/mysql/client_plugin.h

@@ -23,6 +23,30 @@
 */
 #define MYSQL_CLIENT_PLUGIN_INCLUDED
 
+/*
+  On Windows, exports from DLL need to be declared
+  Also, plugin needs to be declared as extern "C" because MSVC 
+  unlike other compilers, uses C++ mangling for variables not only
+  for functions.
+*/
+#if defined(_MSC_VER)
+#if defined(MYSQL_DYNAMIC_PLUGIN)
+  #ifdef __cplusplus
+    #define MYSQL_PLUGIN_EXPORT extern "C" __declspec(dllexport)
+  #else
+    #define MYSQL_PLUGIN_EXPORT __declspec(dllexport)
+  #endif
+#else /* MYSQL_DYNAMIC_PLUGIN */
+  #ifdef __cplusplus
+    #define  MYSQL_PLUGIN_EXPORT extern "C"
+  #else
+    #define MYSQL_PLUGIN_EXPORT 
+  #endif
+#endif /*MYSQL_DYNAMIC_PLUGIN */
+#else /*_MSC_VER */
+#define MYSQL_PLUGIN_EXPORT
+#endif
+
 #ifndef MYSQL_ABI_CHECK
 #include <stdarg.h>
 #include <stdlib.h>
@@ -74,24 +98,8 @@ struct st_mysql_client_plugin_AUTHENTICATION
   int (*authenticate_user)(MYSQL_PLUGIN_VIO *vio, struct st_mysql *mysql);
 };
 
-/**
-  type of the mysql_authentication_dialog_ask function
+#include <mysql/auth_dialog_client.h>
 
-  @param mysql          mysql
-  @param type           type of the input
-                        1 - ordinary string input
-                        2 - password string
-  @param prompt         prompt
-  @param buf            a buffer to store the use input
-  @param buf_len        the length of the buffer
-
-  @retval               a pointer to the user input string.
-                        It may be equal to 'buf' or to 'mysql->password'.
-                        In all other cases it is assumed to be an allocated
-                        string, and the "dialog" plugin will free() it.
-*/
-typedef char *(*mysql_authentication_dialog_ask_t)(struct st_mysql *mysql,
-                      int type, const char *prompt, char *buf, int buf_len);
 /******** using plugins ************/
 
 /**

include/mysql/client_plugin.h.pp

@@ -24,6 +24,8 @@ struct st_mysql_client_plugin_AUTHENTICATION
   int type; unsigned int interface_version; const char *name; const char *author; const char *desc; unsigned int version[3]; const char *license; void *mysql_api; int (*init)(char *, size_t, int, va_list); int (*deinit)(); int (*options)(const char *option, const void *);
   int (*authenticate_user)(MYSQL_PLUGIN_VIO *vio, struct st_mysql *mysql);
 };
+#include <mysql/auth_dialog_client.h>
+struct st_mysql;
 typedef char *(*mysql_authentication_dialog_ask_t)(struct st_mysql *mysql,
                       int type, const char *prompt, char *buf, int buf_len);
 struct st_mysql_client_plugin *