safe shutdown and signal deliverence to all threads in 
the manager process

logging, options, angel process.

5.0 and 4.1 (where it fails).

One test in subselect.test still wrong.
Had to reconstruct all errmsg.txt files completely, since auto-merge made
a mess of the lot. :-(

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

using a hash table instead (and made it work with lex pointers).
Some additional code cleanup too.

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

(now it return correct results. Test was commited before, but it is not pushed,
BUG# is not registered, because bug was introduced after release)

fixed test func_gconcat to be repeatable independent of presend tables and avoid removing user tables

initialization of item_thd moved to constructor (in any case we need thd in constructor)
initialization of group_concat_max_len to constructor to avoid incorrect length reporting (BUG#757)
removed Item_func_group_concat::fix_length_and_dec() because item have its own fix_fields and will not have inherited items

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

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

into bar.mysql.r18.ru:/usr/home/bar/mysql-4.1

  Item_func::agg_arg_collations()
  Item_func::arr_arg_collations_for_comparison()
 to aggregate argument collations.
It helps to reuse a lot of code.

into serg.mylan:/usr/home/serg/Abk/mysql-4.1

into mysql.r18.ru:/usr/home/ram/work/4.1

into serg.mylan:/usr/home/serg/Abk/mysql-4.1

into narttu.mysql.fi:/my/mysql-4.1

into bar.mysql.r18.ru:/usr/home/bar/mysql-4.1

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

  ROW('a','b','c) = ROW('A' collate latin1_bin,'b','c') returns 0
When a number is compared to a string, character sets and 
collations are not aggregated. e.g. this returned error in 4.1.0:

SELECT 1=_latin2'1';
because character sets was aggregated, and 1 was considered as
a string of latin1 charset during this aggregation.

into narttu.mysql.fi:/my/mysql-4.1

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