This should fix some possible table cache corruptions when doing
OPTIMIZE or REPAIR table when other threads are opening new tables.


sql/sql_base.cc:
  Added missing mutex unlock on error condition
sql/sql_insert.cc:
  Added TODO item
sql/sql_show.cc:
  Added missing pthread_mutex_lock(&LOCK_open) when calling
  query_table_status().
sql/sql_table.cc:
  Added missing pthread_mutex_lock(&LOCK_open) when calling
  hash_delete(), unlock_table_name() and remove_table_from_cache().
BitKeeper/etc/logging_ok:
  Logging to logging@openlogging.org accepted