Merge with 4.0 for 4.1 release

Noteworthy:
- New HANDLER code
- New multi-update-grant-check code
- Table lock code in ha_innodb.cc was not applied

sql/sql_class.h

@@ -750,6 +750,7 @@ public:
   */
   MYSQL_LOCK	*lock;				/* Current locks */
   MYSQL_LOCK	*locked_tables;			/* Tables locked with LOCK */
+  HASH		handler_tables_hash;
   /*
     One thread can hold up to one named user-level lock. This variable
     points to a lock object if the lock is present. See item_func.cc and