Code clean-up.

1. Fix for the crash in debug mode when the .frm is corrupted and SHOW TABLE STATUS is executed.This also fixes to return the error message to comment field in SHOW TABLE STATUS when the .frm is corrupted
2. Test for corrupted .frm and the SHOW TABLE STATUS

into mysql.com:/home/wax/mysql-4n

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

columns.

into myvenu.com:/home/venu/work/sql/dev-4.1

Fix for mysql_stmt_close(), so that the PHP layer can map it easily to know whether the 'stmt' is really freed, so that they can free their internal stmts

Increased some tests' robustness a bit :
- Added RESET MASTER to all tests who do SHOW BINLOG EVENTS, to make them independent from previous tests.
- Added save_master_pos to these tests to wait for the slave to start before purging its binary logs.

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

 - removed obsolete compile options from compile-pentium-debug-openssl

  SHOW CHARACTER SET now displays "1" in mb_maxlen even if a charset is not loaded yet

into mysql.r18.ru:/usr/home/ram/work/mysql-4.1

Code cleanup.

(SCRUM)

into mysql.r18.ru:/usr/home/ram/work/mysql-4.1

into gluh.mysql.r18.ru:/home/gluh/mysql-4.1.uvar

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

  InnoDB maps HA_READ_PREFIX_LAST_OR_PREV to PAGE_CUR_LE, but note that only complete-field prefixes of the kay value can be used as the search key

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

"syntax error".