Set null_value in case of wrong data.

Fixes:
- Bug #24089: Race condition in fil_flush_file_spaces()

into  quadxeon.mysql.com:/benchmarks/ext3/TOSAVE/tsmith/bk/41

Pass location of charsets dir to mysqltest to avoid using the charsetdir locally installed on machine. 

into  mysql.com:/Users/kent/mysql/bk/lic/my41-lic

  Added LICENSE.mysql, removed LICENSE.doc README.NW.
  Removed obselete section about MySQLEULA.txt and README.NW.
README:
  Added reference to the EXCEPTIONS-CLIENT file.
  Changed reference to the commercial license file.
  Corrected references into chapters in the manual.
.del-MySQLEULA.txt~4a1afd9284f9be5a:
  Delete: Docs/MySQLEULA.txt

 - Readd --skip-bdb when valgrinding

Correct faulty commit, the opt_tastcase_timeout value is in minutes, to it need to be multiplied with 60 before ping passed to mtr_timer_start 

into  neptunus.(none):/home/msvensson/mysql/mysql-4.1-maint

Make --mem settable with environment variable MTR_MEM and make it possible to pass the directory to use. I.e --mem=<directory>  

into  zippy.cornsilk.net:/home/cmiller/work/mysql/mysql-4.1-maint

  
The Item_func_mod objects never had maybe_null set, so users had no reason 
to expect that they can be NULL, and may therefore deduce wrong results.
Now, set maybe_null.

into  zippy.cornsilk.net:/home/cmiller/work/mysql/mysql-4.1-maint

into  shellback.(none):/home/msvensson/mysql/mysql-4.1-maint

  Raise version number to 4.1.23

into  kpdesk.mysql.com:/home/thek/dev/mysql-4.1-maint

- 'false' not defined in C, use FALSE instead.

into  mysql.com:/usr/home/ram/work/bug22913/my41-bug22913

We don't check for errors that may occur during data printing.

into  bodhi.local:/opt/local/work/mysql-4.1-runtime

into  shellback.(none):/home/msvensson/mysql/mysql-4.1-maint

into  shellback.(none):/home/msvensson/mysql/mysql-4.1-maint

into  kpdesk.mysql.com:/home/thek/dev/mysql-4.1-maint

 - Only read *.pid
 - Only allow it to contain a number 

- Because my_seek actually is capable of returning an error code we should
  exploit that in the best possible way.
- There might be kernel errors or other errors we can't predict and capturing
  the return value of all system calls gives us better understanding of
  possible errors.

into  mysql.com:/usr/home/ram/work/bug23412/my41-bug23412

into  moonlight.intranet:/home/tomash/src/mysql_ab/mysql-4.1-bug21915

If the user has specified --max-connections=N or --table-open-cache=M
options to the server, a warning could be given that some values were
recalculated, and table-open-cache could be assigned greater value.

Note that both warning and increase of table-open-cache were totally
harmless.

This patch fixes recalculation code to ensure that table-open-cache will
be never increased automatically and that a warning will be given only if
some values had to be decreased due to operating system limits.

No test case is provided because we neither can't predict nor control
operating system limits for maximal number of open files.

into  shellback.(none):/home/msvensson/mysql/mysql-4.1-maint

 - Wait in loop with small sleep until tables has been renamed

into  perch.ndb.mysql.com:/home/jonas/src/mysql-4.1-ndb

into  perch.ndb.mysql.com:/home/jonas/src/mysql-4.1-ndb