This changeset adds replication of events and user-defined functions. 
There are several bug reports involved in this change:

BUG#16421, BUG#17857, BUG#20384:
This patch modifies the mysql.events table to permit the addition of
another enum value for the status column. The column now has values
of ('DISABLED','SLAVESIDE_DISABLED','ENABLED'). A status of
SLAVESIDE_DISABLED is set on the slave during replication of events.
This enables users to determine which events werereplicated from the 
master and to later enable them if they promote the slave to a master.
The CREATE, ALTER, and DROP statements are binlogged.
A new test was added for replication of events (rpl_events).

BUG#17671:
This patch modifies the code to permit logging of user-defined functions.
Note: this is the CREATE FUNCTION ... SONAME variety. A more friendly error 
message to be displayed should a replicated user-defined function not be
found in the loadable library or if the library is missing from the
slave.The CREATE andDROP statements are binlogged. A new test was added 
for replication of user-defined functions (rpl_udf). 

The patch also adds a new column to the mysql.event table named
'originator' that is used to store the server_id of the server that
the event originated on. This enables users to promote a slave to a 
master and later return the promoted slave to a slave and disable the
replicated events.

          SF/Triggers in SBR mode."
BUG#14914 "SP: Uses of session variables in routines are not always replicated"
BUG#25167 "Dupl. usage of user-variables in trigger/function is not replicated
          correctly"

This patch corrects a minor error in the previous patch for BUG#20141. This patch
corrects an errant code change to sp_head.cc. The comments for the first patch follow:

User-defined variables used inside of stored functions/triggers in
statements which did not update tables directly were not replicated.
We also had problems with replication of user-defined variables which
were used in triggers (or stored functions called from table-updating
statements) more than once.

This patch addresses the first issue by enabling logging of all
references to user-defined variables in triggers/stored functions
and not only references from table-updating statements.

The second issue stemmed from the fact that for user-defined
variables used from triggers or stored functions called from
table-updating statements we were writing binlog events for each
reference instead of only one event for the first reference.
This problem is already solved for stored functions called from
non-updating statements with help of "event unioning" mechanism.
So the patch simply extends this mechanism to the case affected.
It also fixes small problem in this mechanism which caused wrong
logging of references to user-variables in cases when non-updating
statement called several stored functions which used the same
variable and some of these function calls were omitted from binlog
as they were not updating any tables.

into  mysql_cab_desk.:C:/source/C++/mysql-5.1-new-rpl

          SF/Triggers in SBR mode."
BUG#14914 "SP: Uses of session variables in routines are not always replicated"
BUG#25167 "Dupl. usage of user-variables in trigger/function is not replicated
          correctly"

User-defined variables used inside of stored functions/triggers in
statements which did not update tables directly were not replicated.
We also had problems with replication of user-defined variables which
were used in triggers (or stored functions called from table-updating
statements) more than once.

This patch addresses the first issue by enabling logging of all
references to user-defined variables in triggers/stored functions
and not only references from table-updating statements.

The second issue stemmed from the fact that for user-defined
variables used from triggers or stored functions called from
table-updating statements we were writing binlog events for each
reference instead of only one event for the first reference.
This problem is already solved for stored functions called from
non-updating statements with help of "event unioning" mechanism.
So the patch simply extends this mechanism to the case affected.
It also fixes small problem in this mechanism which caused wrong
logging of references to user-variables in cases when non-updating
statement called several stored functions which used the same
variable and some of these function calls were omitted from binlog
as they were not updating any tables.

Adding code to release allocated memory when tables_to_lock list is
cleared.

into  romeo.(none):/home/bk/b25091-mysql-5.1-new-rpl

into  romeo.(none):/home/bk/b25091-mysql-5.1-new-rpl

With this patch, statements that change metadata (in the mysql database)
is logged as statements, while normal changes (e.g., using INSERT, DELETE,
and/or UPDATE) is logged according to the format in effect.

The log tables (i.e., general_log and slow_log) are not replicated at all.

With this patch, the following statements are replicated as statements:
GRANT, REVOKE (ALL), CREATE USER, DROP USER, and RENAME USER.

into  mysql.com:/nfsdisk1/lars/MERGE/mysql-5.1-merge

into  mysql.com:/nfsdisk1/lars/MERGE/mysql-5.1-merge

into  mysql.com:/nfsdisk1/lars/MERGE/mysql-5.0-merge

into  mysql.com:/nfsdisk1/lars/MERGE/mysql-5.1-merge

into  mysql.com:/nfsdisk1/lars/MERGE/mysql-5.0-merge

into  mysql.com:/nfsdisk1/lars/MERGE/mysql-4.1-merge

into  romeo.(none):/home/bk/b26286-mysql-5.1-rpl

  fix after merge: server now returns ER_DUP_ENTRY_WITH_KEY_NAME, not ER_DUP_ENTRY

into  romeo.(none):/home/bk/b26286-mysql-5.1-rpl

Submitting patch on Guilhem's behalf (he found the solution).
  
Correcting a typo that caused very big increases in memory usage when
more memory needed to be allocated for row-based events. Also correcting
a border case check when more memory needed to be allocated.

into  mysql.com:/nfsdisk1/lars/MERGE/mysql-5.1-merge

into  mysql.com:/nfsdisk1/lars/MERGE/mysql-5.0-merge

into  mysql.com:/nfsdisk1/lars/MERGE/mysql-5.1-merge

into  mysql.com:/nfsdisk1/lars/MERGE/mysql-5.0-merge

into  mysql.com:/nfsdisk1/lars/MERGE/mysql-4.1-merge

mysqlbinlog prints all row-based events of a single statement as a
single "BINLOG" statement containing the concatenation of those events.
Big (i.e. >64k) concatenations of row-based events
(e.g. Write_rows_log_event) caused mysqlbinlog's IO_CACHE to overflow
to a temporary file but the IO_CACHE had not been inited with
open_cached_file(), so it tried to create a temporary file in
an uninitialized directory (thus failing to create, then to write;
some OS errors were printed, and it finally segfaulted).
After fixing this, it appeared that mysqlbinlog was printing only
a piece of big concatenations of row-based events (it printed
at most the size of the IO_CACHE's buffer i.e. 64k); that caused data
loss at restore. We fix and test that.
Last, mysqlbinlog's printouts looked a bit strange with the informative
header (#-prefixed) of groupped Rows_log_event all on one line,
so we insert \n. After that, a small bug in the --hexdump code appeared
(only if the string to hex-print had its length a multiple of 16),
we fix it.

into  dl145h.mysql.com:/users/gbichot/mysql-5.1-rpl

Post-merge fixes.

  "INSERT... ON DUPLICATE KEY UPDATE skips auto_increment values"
didn't make it into 5.0.36 and 5.1.16,
so we need to adjust the bug-detection-based-on-version-number code.
Because the rpl tree has a too old version, rpl_insert_id cannot pass,
so I disable it (like is already the case in 5.1-rpl for the same reason),
and the repl team will re-enable it when they merge 5.0 and 5.1 into
their trees (thus getting the right version number).

into  romeo.(none):/home/bk/b19033-mysql-5.1-new-rpl

into  mysql.com:/home/my/mysql-5.1

Fixed compile-pentium64 scripts
Fixed wrong estimate of update_with_key_prefix in sql-bench
Merge bk-internal.mysql.com:/home/bk/mysql-5.1 into mysql.com:/home/my/mysql-5.1
Fixed unsafe define of uint4korr()
Fixed that --extern works with mysql-test-run.pl
Small trivial cleanups
This also fixes a bug in counting number of rows that are updated when we have many simultanous queries
Move all connection handling and command exectuion main loop from sql_parse.cc to sql_connection.cc
Split handle_one_connection() into reusable sub functions.
Split create_new_thread() into reusable sub functions.
Added thread_scheduler; Preliminary interface code for future thread_handling code.

Use 'my_thread_id' for internal thread id's
Make thr_alarm_kill() to depend on thread_id instead of thread
Make thr_abort_locks_for_thread() depend on thread_id instead of thread
In store_globals(), set my_thread_var->id to be thd->thread_id.
Use my_thread_var->id as basis for my_thread_name()
The above changes makes the connection we have between THD and threads more soft.

Added a lot of DBUG_PRINT() and DBUG_ASSERT() functions
Fixed compiler warnings
Fixed core dumps when running with --debug
Removed setting of signal masks (was never used)
Made event code call pthread_exit() (portability fix)
Fixed that event code doesn't call DBUG_xxx functions before my_thread_init() is called.
Made handling of thread_id and thd->variables.pseudo_thread_id uniform.
Removed one common 'not freed memory' warning from mysqltest
Fixed a couple of usage of not initialized warnings (unlikely cases)
Suppress compiler warnings from bdb and (for the moment) warnings from ndb

into  mysql.com:/home/my/mysql-5.0

Suppress compiler warnings from bdb and (for the moment) warnings from ndb

Fixed a couple of usage of not initialized warnings (unlikely cases)