Remove the question of Monty about user_thd / NULL after a merge from 4.0 to 4.1, user_thd is the right value in 4.1

This fixes a problem with SHOW PROCESSLIST

This fixes a possible core dump problem in SHOW PROCESSLIST

into myvenu.com:/home/venu/work/sql/dev-4.1

into myvenu.com:/home/venu/bk/src-4.1

into eagle.mysql.r18.ru:/home/vva/work/add_libedit/experiment/4.1.control

into eagle.mysql.r18.ru:/home/vva/work/add_libedit/experiment/4.1.clone

Don't use new password format if mysql.user has old format
tables_priv was not reset on FLUSH PRIVILEGES if tables_priv was empty
Portability fixes for Windows

into hundin.mysql.fi:/home/heikki/mysql

  Backport from 4.0: fix bug in adaptive hash index search

  Fix a crash in page_dir_find_owner_slot if an adaptive hash index search coincides with purge or an insert

into eagle.mysql.r18.ru:/home/vva/work/mysql.orig/try_compile/4.1

into sanja.is.com.ua:/home/bell/mysql/work-ctype-4.1

into eagle.mysql.r18.ru:/home/vva/work/BINLOG_LOADDATA/4.1.clear

into eagle.mysql.r18.ru:/home/vva/work/BINLOG_LOADDATA/4.1.clear

into eagle.mysql.r18.ru:/home/vva/work/BINLOG_LOADDATA/4.1.clear

Allow one to change ANSI_QUOTES mode per thread and on the fly

into sanja.is.com.ua:/home/bell/mysql/work-ctype-4.1