Moved a lot of old bug fixes and safe cleanups from Maria 5.1 tree to 5.1

- Reserver namespace and place in frm for TABLE_CHECKSUM and PAGE_CHECKSUM create options
- Added syncing of directory when creating .frm files
- Portability fixes
- Added missing cast that could cause bugs
- Code cleanups
- Made some bit functions inline
- Moved things out of myisam.h to my_handler.h to make them more accessable
- Renamed some myisam variables and defines to make them more globaly usable (as they are used outside of MyISAM)
- Fixed bugs in error conditions
- Use compiler time asserts instead of run time
- Fixed indentation
HA_EXTRA_PREPARE_FOR_DELETE -> HA_EXTRA_PREPARE_FOR_DROP as the old name was wrong
(Added a define for old value to ensure we don't break any old code)
Added HA_EXTRA_PREPARE_FOR_RENAME as a signal for rename (before we used a DROP signal which is wrong)
- Initialize error messages early to get better errors when mysqld or an engine fails to start
- Fix windows bug that query_performance_frequency was not initialized if registry code failed
- thread_stack -> my_thread_stack_size

sql/sql_class.cc

@@ -440,6 +440,7 @@ THD::THD()
   cleanup_done= abort_on_warning= no_warnings_for_error= 0;
   peer_port= 0;					// For SHOW PROCESSLIST
   transaction.m_pending_rows_event= 0;
+  transaction.on= 1;
 #ifdef SIGNAL_WITH_VIO_CLOSE
   active_vio = 0;
 #endif