Merge manually the InnoDB mysqldump -l crash patch (crash with LOCK TABLES ... LOCAL) from 4.0 to 4.1; some code cleanup

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

into poseidon.ndb.mysql.com:/home/tomas/mysql-4.1

function being used before it was defined - "forward" declaration
was insufficient.

differently when converting column to auto_increment in 4.1" with
current tree.

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

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

into poseidon.ndb.mysql.com:/home/tomas/mysql-4.1

to auto_increment in 4.1".
Now we are enforcing NO_AUTO_VALUE_ON_ZERO mode during ALTER TABLE only
if we are converting one auto_increment column to another auto_increment
column (this also includes most common case when we don't do anything
with such column).

Also now when we convert some column to TIMESTAMP NOT NULL column with
ALTER TABLE we convert NULL values to current timestamp, (as we do this
in INSERT). One can still get old behavior by setting system TIMESTAMP
variable to 0.

into brian-akers-computer.local:/Users/brian/mysql/mysql-4.1

Some bigger code changes was necessary becasue of the multi-table-update and the new HANDLER code

Clean up from Bar and Antony code review. Found an issue with the header file were it could end up corrupted.

into build.mysql.com:/users/rburnett/mysql-4.0

mysqld.cc:
  Added call to create_pid_file to start_signal_handler on windows.  Also removed the #ifndef WINDOWS from two calls that deletes the pid file

Noteworthy:
- New HANDLER code
- New multi-update-grant-check code
- Table lock code in ha_innodb.cc was not applied

and testcases

into gw.mysql.r18.ru:/usr/home/ram/work/4.0.b5733

into brian-akers-computer.local:/Users/brian/mysql/mysql-4.1

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

Cleaned up patch for checking locks for multi-table updates

into mysql.com:/home/dlenev/src/mysql-4.1-bf

introduced during implementation of TIMESTAMP columns, which are able 
to store NULLs (Unfortunately it is impossible to write test case for
this. Kudos to Holyfoot for noticing it!)

into deer.(none):/home/hf/work/mysql-4.1.5730

  Fix typos in previous push

into hundin.mysql.fi:/home/heikki/mysql-4.1

into poseidon.ndb.mysql.com:/home/tomas/mysql-4.1

into deer.(none):/home/hf/work/mysql-4.0

Recusive part leads to stack overflow

into hundin.mysql.fi:/home/marko/k/mysql-4.0

  Raise maximum column prefix len to 767 bytes, so that MySQL can create a column prefix index of 255 UTF-8 characters (each takes 3 bytes at the maximum); add comments about why innobase_get_at_most_n_mbchars() works ok
dict0mem.h:
  Raise maximum column prefix len to 767 bytes, so that MySQL can create a column prefix index of 255 UTF-8 characters (each takes 3 bytes at the maximum)
row0mysql.c:
  If MySQL tries to create a column prefix index longer that 255 UTF-8 characters, give an error, and drop the table from the InnoDB internal data dictionary. MySQL did not drop the table there in its own error handling.

into hundin.mysql.fi:/home/marko/j/mysql-4.1