accomodate EXPLAIN properly for all possible variant of UNION's
derived tables etc ...

This also fixes all reported (and unreported) bugs when EXPLAIN is
run on UNION's.

select_describe() now has a very dirty hack to avoid some problems
with transactional tables on table unlocking.

Code speedup is possible. For the moment all that was important was
that all tests are passed.

into sinisa.nasamreza.org:/mnt/hdc/Sinisa/mysql-4.0

  Experiment

  @uref fix-ups
include.de.texi:
  new file

  new file

into co3064164-a.bitbike.com:/home/arjen/mysql-4.0

into sinisa.nasamreza.org:/mnt/hdc/Sinisa/mysql-4.0

into co3064164-a.bitbike.com:/home/arjen/mysql-4.0

Fixed typo.

into sinisa.nasamreza.org:/mnt/hdc/Sinisa/mysql-4.0

Added update about PostgreSQL 7.2 and VACUUM.

into linux.local:/home/zak/bk/mysql-4.0

  Fix typo in a contrib download filename

into sarvik.tfr.cafe.ee:/usr/home/tfr/BK/mysql-4.0

  Remove link to sqlscreens in the contrib section

Added mention of USE/IGNORE KEY as alias for USE/IGNORE INDEX.
Fixups references to this feature throughout manual.

  Add a warning to drop database wait if there are still open handles on a table

  Add some more safety if MySQL tries to drop a table on which there are open handles