parallel read access to IO_CACHE

into sergbook.mysql.com:/usr/home/serg/Abk/mysql-4.0

Various cleanups in News 4.0.2 section.

into teton.kitebird.com:/home/paul/mysql-4.0

into rhols221.adsl.netsonic.fi:/home/my/bk/mysql-4.0

Read a manual for more detail

into hegel.local:/home/miguel/dev/mysql-4.0

into fred.bitbike.com:/home/arjen/mysql-4.0

- Fixed some bugs, wrongly freed pointers, in some clients.
- Removed unneccessary code.
- Fixed some other minor bugs and added some options into
  variables category, which had accidently been left out earlier.

manual.texi	operands, not arguments.

manual.texi	behavior to return NULL, not zero, if either operand is NULL)

into sergbook.mysql.com:/usr/home/serg/Abk/mysql-4.0

into mugatu.spaceapes.com:/home/jcole/bk/mysql-4.0

- Added special option/variable prefix '--loose-' to my_getopt.c

(--prompt code contributed by Harrison Fisk.)
Made mysql subsection title clear.
Little style cleanups.