Removed forgotten EXPLAIN EXTENDED from the test file.

Automerged with 5.3.

- Added regression test with queries over the WORLD database.
- Discovered and fixed several bugs in the related cost calculation
  functionality both in the semijoin and non-semijon subquery code.
- Added DBUG printing of the cost variables used to decide between
  IN-EXISTS and MATERIALIZATION.

-In  do_sj_dups_weedout(), set nulls_ptr to point to NULL bytes (and not to length bytes) of the DuplicateWeedout column.

- Testcase

BUG#761598: InnoDB: Error: row_search_for_mysql() is called without ha_innobase::external_lock() in maria-5.3
- Testcase

- Add testcase

The previous patch partially fixed things by waiting for the old dump thread
on the master to exit before injecting the DBUG error. This prevents the error
injection going to the wrong thread.

However, there is still the problem that the old dump thread may never exit,
causing the wait to time out. This happens if the dump thread manages to write
all events down the socket before the socket is closed by the slave. The
master dump thread only checks for slave gone when writing a new event, so if
no new events are generated, old dump threads can hang around forever on the
master after the slave disconnects.

Fix by explicitly killing the old dump thread if it is still around.

(Changeset sp1r-igor@olga.mysql.com-20070526173301-38848 moved this loop from one place 
to another, then the merge of sp1r-gshchepa/uchum@gleb.loc-20070527192244-26330  have 
kept both copies).

- move attempt to evaluate join->exec_const_cond() out of the "Extract constant part of each ON expression" loop
  (it got there by mistake when merging).

mysql-test/suite/maria/t/maria3.test:
  Fix when compiling with safemalloc
storage/maria/ha_maria.cc:
  Fix that MAX_FILE_SIZE is not limited on 32 bit machines.

- Add a testcase (the bug has already been fixed)

- Handle the case when the subquery's join is degenerate and so has zero tables.

from an ad hoc set of limitations
to a correct rule

Fixed reference to not initialized memory detected by valgrind

sql/sql_select.cc:
  A bit better fix for tmp-table problem:
  Use only dynamic_record format for group by and distinct.
storage/maria/ma_create.c:
  DYNAMIC_RECORD format doesn't pack VARCHAR fields.
  This change fixes a non-fatal uninitialized memory copy.

The function generate_derived_keys did not take into account the fact
that the last element in the array of keyuses could be just a barrier
element. In some cases it could lead to a crash of the server.

Also fixed a couple of other bugs in generate_derived_keys: the inner 
loop in the body of if this function did not change the cycle variables
properly.

The reason for this is that BLOCK_RECORD format is not good when there is a lot of duplicated keys as it first writes the data (to get the row position) and
then writes the key (and thus checks for duplicates).

Fix Field_time_hires::reset()

  microsecond(TIME)
  alter table datetime<->datetime(6)
  max(TIME), mix(TIME) 

mysql-test/t/func_if.test:
  fix the test case of avoid overflow
sql/field.cc:
  don't use make_date() and make_time()
sql/field.h:
  correct eq_def() for temporal fields
sql/item.cc:
  move datetime caching from Item_cache_int
  to Item_cache_temporal
sql/item.h:
  move datetime caching from Item_cache_int
  to Item_cache_temporal
sql/item_func.cc:
  use existing helper methods, don't duplicate
sql/item_sum.cc:
  argument cache must use argument's cmp_type, not result_type.
sql/item_timefunc.cc:
  use existing methods, don't tuplicate.
  remove unused function.
  fix micorseconds() to support TIME argument
sql/mysql_priv.h:
  dead code
sql/time.cc:
  dead code

Fixed problem that global status variables 'bytes_recieved' and 'binlog_bytes_written' where not correctly updated 

Fixed crash when setting query_cache_type to 0.

client/Makefile.am:
  Added zlib include (needed by checksum.c)
sql/set_var.cc:
  Updated call to disable_query_cache()
sql/sql_cache.cc:
  Don't give warning if we start mysqld with --query_cache_type=0 --query_cache-size=0
  Fixed crash when setting query_cache_type to 0 (we shouldn't call query_cache.disable_query_cache() when there is no current_thd)
sql/sql_cache.h:
  Added THD to disable_query_cache()

strings/ctype-simple.c:
  Fixed some compiler warnings

INSERT/UPDATE/DELETE statement that used a temptable view v1 could lead to
a crash if v1 was defined as a select from a mergeable view v2 that selected
rows from a temptable view v3. 
 
When INSERT/UPDATE/DELETE uses a view that is not updatable then field
translation for the view should be created before the prepare phase.

After talking to HeidiSQL people -  libmysql.dll that comes with their distribution in place, dont replace with our own.
It also will result in less HeidiSQL restarts during MariaDB upgrades (since libmysql.dll won't be replaced)

VS did not like to execute 2 commands in custom build step, workaround is 
to use single COMMAND instead of 2.