Setting insert delayed threads = 0 at mysql_init_command.


sql/mysql_priv.h:
  New session variable, max_insert_delayed_threads
sql/mysqld.cc:
  New session variable, max_insert_delayed_threads
sql/set_var.cc:
  New session variable, max_insert_delayed_threads
sql/sql_class.h:
  New session variable, max_insert_delayed_threads
sql/sql_insert.cc:
  New session variable, max_insert_delayed_threads
BitKeeper/etc/logging_ok:
  Logging to logging@openlogging.org accepted