Improved definition of mysys configuration for -nt builds.

Make sure for the mysys project that __NT__ is defined in *nt solution
configurations (but not in other configurations).

into  mysql.com:/home/alexi/bugs/mysql-5.0-19208

 and BUG#19208 "Test 'rpl000017' hangs on Windows".
 Both bugs are caused by attempting to delete an opened
 file and to create immediatedly a new one with the same
 name. On Windows it can be supported only on NT-platforms
 (by using FILE_SHARE_DELETE mode and with renaming the
 file before deletion). Because deleting not-closed files
 is not supported on all platforms (e.g. Win 98|ME) this
 is to be considered harmful and should be eliminated by
 a "code redesign".

into  mysql.com:/users/lthalmann/bk/MERGE/mysql-5.0-merge

Sometimes the helper connection (that is watching for the main connection
to time out) would itself time out first, causing the test to fail.

into  mysql.com:/users/lthalmann/bk/MERGE/mysql-5.0-merge

into  mysql.com:/home/emurphy/mysql-5.0-heikki

Fixes bug#17264, for alter table on win32 for successfull operation completion
it is used TL_WRITE(=10) lock instead of TL_WRITE_ALLOW_READ(=6), however here
in innodb handler TL_WRTIE is lifted to TL_WRITE_ALLOW_WRITE, which causes
race condition when several clients do alter table simultaneously.

into  mysql.com:/mnt/storeage/mysql-5.0

into sunlight.local:/home/evgen/tmp_merge-5.0-opt-mysql

  After merge fix

  After merge fix

into  mysql.com:/home/stewart/Documents/MySQL/5.0/bugsmerge

into  mysql.com:/users/lthalmann/bk/MERGE/mysql-5.0-merge

into  mysql.com:/users/lthalmann/bk/MERGE/mysql-5.0-merge

  Reverted fix for bug#18360

into  mysql.com:/home/alik/MySQL/devel/5.0-tree-merged

into  mysql.com:/home/alik/MySQL/devel/5.0-rt

BUG#18036 - update of table joined to self reports table as crashed

Set exclude_from_table_unique_test value back to FALSE. It is needed for
further check in multi_update::prepare whether to use record cache.

into  mysql.com:/users/lthalmann/bk/MERGE/mysql-5.0-merge

into  may.pils.ru:/home/svoj/devel/mysql/BUG18036/mysql-5.0

into  may.pils.ru:/home/svoj/devel/mysql/BUG18036/mysql-5.0

  - fix for IM stopping routine;
  - polishing.

can be started several times; monitor interval must be > 2sec

into  mysql.com:/users/lthalmann/bk/MERGE/mysql-5.0-merge

into  mysql.com:/users/lthalmann/bk/MERGE/mysql-4.1-merge

into  may.pils.ru:/home/svoj/devel/mysql/BUG18036/mysql-4.1

Certain updates of table joined to self results in unexpected
behavior.

The problem was that record cache was mistakenly enabled for
self-joined table updates. Normally record cache must be disabled
for such updates.

Fixed wrong condition in code that determines whether to use
record cache for self-joined table updates.

Only MyISAM tables were affected.

into moonbone.local:/work/tmp_merge-5.0-opt-mysql

into moonbone.local:/work/tmp_merge-5.0-opt-mysql

into moonbone.local:/work/tmp_merge-4.1-opt-mysql