Merge mysql.com:/home/hf/work/mrg/mysql-5.0-opt

into  mysql.com:/home/hf/work/mrg/mysql-5.1-opt


sql/item.h:
  Auto merged
sql/sql_base.cc:
  Auto merged
sql/sql_select.cc:
  Auto merged
sql/sql_yacc.yy:
  Auto merged