table resolution".
Added members to Item_ident for storing original db, table and field
names since those that set later from Field have shorter life-time 
than required by prep. stmt. So we need to restore original names in 
Item_ident::cleanup(). Also now using special construnctor for creation
of Item_field from Field object that ensures that table and field name 
have big enough life-time.

"Fix" for bug #2050 "10 to 1 performance drop with server 4.1.1"
Clean ups in implementation of caching of field number in table.
Added caching of table in which field is found in find_field_in_tables(). 

into gluh.mysql.r18.ru:/home/gluh/Bugs/mysql-4.1

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

Marked --no-set-names as deprecated, the name is misleading and --no- in front
makes it cumbersome to use with --disable or --skip prefixes.
The old option will still work for the time being.

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

Portability fixes

implemented in the client library and server.
Warning: this makes the new client library and server incompatible with all 
previous versions and 5.0.

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

Collation gets lost in CREATE TABLE (...) DEFAULT CHARACTER SET xxx COLLATE yyy

This is fixed now.
Test is added into the test suite.

Forgot to do it in the previous commit.

and for (2) converting the columns:

1.  ALTER TABLE t1 [DEFAULT] CHARACTER SET xxx [COLLATE yyy]
2.  ALTER TABLE t1 CONVERT TO CHARACTER SET xxx [COLLATE yyy]

ChangeSet
  1.1707 04/03/19 12:36:55 ram@gw.mysql.r18.ru +4 -0
  Fix for the bug #2976: NATURAL JOIN produces duplicate columns.

Fixes after last merge

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

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

into mysql.com:/home/my/mysql-4.0

SET character_set_xxx=NULL
and
SET collation_xxx=NULL

  More clear error message.

No need to check for result existence any more, store_result functions
now are shorter.
cli_read_binary_rows rewritten to handle MYSQL_DATA directly.

Actually it is not a bug but right behavior observed as pefomance 
degradation after we have forced Item_field::fix_fields() to 
re-execute each time when we are executing prep stmt.

This patch implements small optimization which heals this bad 
behavior. We are caching field position in TABLE::field array in
Item's member and are using this position for speeding up field
lookups in fix_fields() in case of its re-execution.