Fixed memory leak in new filesort code
Optimzed sub selects to use keys with outer references.
Increased max tables in join to 62

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

into sinisa.nasamreza.org:/mnt/work/mysql-4.1

was not properly stored in the buffer.

into deer.mysql.r18.ru:/home/hf/work/mysql-4.1.cursor

Protocol_cursor task
net_field_length definitions trimmed with Monty's suggestions

TMP_TABLE_PARAM.
This involved moving things around in include files.
All tests, including the ones with Valgrind passed.

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

into hundin.mysql.fi:/home/igor/dev/mysql-4.1

into eagle.mysql.r18.ru:/home/vva/work/COMPRESS_UNCOMPRESS/mysql-4.1

is executed, even if the transaction spans on >=2 relay logs (bug #53).
New variable relay_log_purge =0|1
New test to verify bug #53

   Added the MAX_LENGTH_FOR_SORT_DATA option
ctype_collate.result:
  Added the MAX_LENGTH_FOR_SORT_DATA option

   Added the MAX_LENGTH_FOR_SORT_DATA option
filesort.cc:
  Added the MAX_LENGTH_FOR_SORT_DATA option

Protocol_cursor class and sql-common/ directory

  We don't need this code any more. It was used to initialize CONVERT structure in 4.0.

  client_collation -> collation_client
  result_collation -> collation_results
  connection_collation -> collation_connection

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

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

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

into eagle.mysql.r18.ru:/home/vva/work/COMPRESS_UNCOMPRESS/mysql-4.1

Remove the 'fs' file systems as this is not maintained.
Moved programs from client to tests

  Table name cache is case-sensitive now like in 4.0.

  Turbo() is not used anymore for multibyte charsets.

Very nasty bug.
It was caused by double free()-ing memory of join->select and 
join->quick. 

I was able to pinpoint it only after using Valgrind.

Plus better fix for bug with TMP_TABLE_PARAM.

Plus new constructor for SELECT_LEX.