fixing names length. Got an issue when merged to 5.0, decided to fix starting from 4.1

fixing a path to find charset by $MYSQL client. I believe the fix is done what should be
by default. 

into  mysql.com:/usr_rh9/home/elkin.rh9/MySQL/Merge/4.1

into  mysql.com:/usr_rh9/home/elkin.rh9/MySQL/Merge/4.1

  A pattern to generate binlog for DROPped temp table in close_temporary_tables
  was buggy: could not deal with a grave-accent-in-name table.

  The fix exploits `append_identifier()' for quoting and duplicating accents.

  Change mode to -rw-rw-r--
Ereport.pl, Ecreate.pl, Ecompare.pl:
  Change mode to -rwxrwxr--

  Change mode to -rw-rw-r--
dbug_add_tags.pl:
  Change mode to -rwxrwxr--

  Stepped up to 4.0.28

into  mysql.com:/home/mysql-4.1-10418

  Compile in all character sets in Max (bug#14918)

into  mysql.com:/usr/home/ram/work/4.1.b18501

Binlog lacks encoding info about DROPped temporary table.

Idea of the fix is to switch temporary to system_charset_info when a temporary table
is DROPped for binlog. Since that is the server, that automatically, but not the client, who generates the query
the binlog should be updated on the server's encoding for the coming DROP.
The `write_binlog_with_system_charset()' is introduced to replace similar problematic places in the code.

load_file() string-function should return NULL rather than throw an error if
the file doesn't exist, as per the manual.

into  rurik.mysql.com:/home/igor/mysql-4.1

into  mysql.com:/usr_rh9/home/elkin.rh9/MySQL/FIXES/4.1-bug19136_unass_user_var

A query with a group by and having clauses could return a wrong
result set if the having condition contained a constant conjunct 
evaluated to FALSE.
It happened because the pushdown condition for table with
grouping columns lost its constant conjuncts.
Pushdown conditions are always built by the function make_cond_for_table
that ignores constant conjuncts. This is apparently not correct when
constant false conjuncts are present.

into mysql.com:/home/psergey/mysql-4.1-bug16798

into  mysql.com:/home/tomash/src/mysql_ab/mysql-4.1-bug16501

into  mysql.com:/home/mydev/mysql-4.0-bug10405

into  mysql.com:/home/tomash/src/mysql_ab/mysql-4.1-bug16501

into  mysql.com:/home/mydev/mysql-4.1-bug10405

into mysql.com:/home/psergey/mysql-4.1-bug16798

The bug was as follows: When merge_key_fields() encounters "t.key=X OR t.key=Y" it will 
try to join them into ref_or_null access via "t.key=X OR NULL". In order to make this 
inference it checks if Y<=>NULL, ignoring the fact that value of Y may be not yet known.

The fix is that the check if Y<=>NULL is made only if value of Y is known (i.e. it is a
constant).
TODO: When merging to 5.0, replace used_tables() with const_item() everywhere in merge_key_fields().

The reason of the bug is in that `get_var_with_binlog' performs missed
assingment of
the variables as side-effect. Doing that it eventually calls
`free_underlaid_joins' to pass as an argument `thd->lex->select_lex' of the lex
which belongs to the user query, not 
to one which is emulated i.e SET @var1:=NULL.


`get_var_with_binlog' is refined to supply a temporary lex to sql_set_variables's stack.

into  mysql.com:/home/tomash/src/mysql_ab/mysql-4.1-bug16372

into  mysql.com:/home/tomash/src/mysql_ab/mysql-4.1-bug16372

into  mysql.com:/home/tomash/src/mysql_ab/mysql-4.1-bug16501

into  polar.kitebird.com:/src/extern/MySQL/bk/mysql-4.1

  Delete: Docs/changelog-4.1.xml

into  polar.kitebird.com:/src/extern/MySQL/bk/mysql-4.1

  Delete: Docs/changelog-4.0.xml

into  ua141d10.elisa.omakaista.fi:/home/my/bk/mysql-4.1

TIME_FORMAT using "%l:%i" returns 36:00 with 24:00:00 in TIME column

into  a193-229-222-105.elisa-laajakaista.fi:/home/my/bk/mysql-4.1

into  mysql.com:/home/tomash/src/mysql_ab/mysql-4.1-bug16372

into  mysql.com:/home/tomash/src/mysql_ab/mysql-4.1-bug16501