Merge with MySQL 5.1, with following additions:

- Moved some code from innodb_plugin to xtradb, to ensure that all tests runs
- Did changes in pbxt and maria storage engines becasue of changes in thd->query
- Reverted wrong code in sql_table.cc for how ROW_FORMAT is used.

This is a re-commit of Monty's merge to eliminate an extra commit from
MySQL-5.1.42 that was accidentally included in the merge.

This is a merge of the MySQL 5.1.41 clone-off (clone-5.1.41-build). In
case there are any extra changes done before final MySQL 5.1.41
release, these will need to be merged later before MariaDB 5.1.41
release.

sql/udf_example.c

@@ -139,12 +139,12 @@ typedef long long longlong;
 #include <mysql.h>
 #include <ctype.h>
 
+#ifdef HAVE_DLOPEN
+
 #if !defined(HAVE_GETHOSTBYADDR_R) || !defined(HAVE_SOLARIS_STYLE_GETHOST)
 static pthread_mutex_t LOCK_hostname;
 #endif
 
-#ifdef HAVE_DLOPEN
-
 /* These must be right or mysqld will not find the symbol! */
 
 my_bool metaphon_init(UDF_INIT *initid, UDF_ARGS *args, char *message);