mysql-test/r/union.result:
  New results for optional UNION syntax
mysql-test/t/union.test:
  New  test for alternate syntax for UNION
sql/sql_delete.cc:
  Fixed bug in multi-table delete's with transactional tables
sql/sql_parse.cc:
  A small change to enable new UNION syntax
sql/sql_union.cc:
  New alternate UNION syntax
sql/sql_yacc.yy:
  New alternate UNION syntax