SQL_SELECT_LIMIT as default will be applied only for SELECT statement if there was not explicit LIMIT clause
correct table list passed to class constructor of select_update


mysql-test/r/subselect.result:
  do not show limit if it is not explicit
mysql-test/r/union.result:
  test of LIMIT + ORDER
mysql-test/t/union.test:
  test of LIMIT + ORDER
sql/ha_isammrg.h:
  caching of queries with isammerge tables forbiden
sql/sql_cache.cc:
  removed check on isammerge
sql/sql_lex.cc:
  tag of explicit limit in statement
sql/sql_lex.h:
  tag of explicit limit in statement
sql/sql_parse.cc:
  blanks in empty line removed
  no limit by default (SQL_SELECT_LIMIT as default will be applied only for SELECT statement if there was not explicit LIMIT clause)
sql/sql_union.cc:
  reverted incorrect patch
sql/sql_update.cc:
  reverted incorrect patch
  correct table list passed to class constructor
sql/sql_yacc.yy:
  explicit LIMIT marked