post-merge fixes: format string was changed 5.0 -> 5.1, resulting in longer output

into  sin.intern.azundris.com:/misc/mysql/31588/51-31588

into  sin.intern.azundris.com:/misc/mysql/31588/50-31588

Buffer used when setting variables was not dimensioned to accomodate
trailing '\0'. An overflow by one character was therefore possible.
CS corrects limits to prevent such overflows.

into  magare.gmz:/home/kgeorge/mysql/autopush/B27099-5.1-opt

move 'table_collation' field filling outside of if(file) condition
because this field has 'OPEN_FRM_ONLY' attribute

into  mysql.com:/home/gluh/MySQL/Merge/5.1-opt

updated result files

into  mysql.com:/home/gluh/MySQL/Merge/5.1-opt

into  mysql.com:/home/gluh/MySQL/Merge/5.0-opt

On Windows the debug log was doing freopen () instead of
fflush() and that was slowing the logging down that much 
that some tests timed out.
Fixed by replacing the freopen() with an syncing-to-disk
flag to fopen() and fflush().
Also increased the timeout of the tests running with --debug
on windows : seems to slow down as much as valgrind on linux.

issue an error if string has illegal characters

into  gleb.loc:/home/uchum/work/bk/5.1-opt

into  gleb.loc:/home/uchum/work/bk/5.0-opt

into  magare.gmz:/home/kgeorge/mysql/autopush/B31156-5.1-opt

  Fixed dbug macros usage errors

into  magare.gmz:/home/kgeorge/mysql/work/B31156-5.1-opt

into  magare.gmz:/home/kgeorge/mysql/autopush/B31156-5.0-opt

into  magare.gmz:/home/kgeorge/mysql/autopush/B31440-5.1-opt

into  magare.gmz:/home/kgeorge/mysql/autopush/B31440-5.0-opt

into  gleb.loc:/home/uchum/work/bk/5.1-opt

into  gleb.loc:/home/uchum/work/bk/5.0-opt

into  magare.gmz:/home/kgeorge/mysql/work/B31440-5.1-opt

into  magare.gmz:/home/kgeorge/mysql/autopush/B31440-5.0-opt

into  mysql.com:/home/hf/work/31155/my51-31155

into  mysql.com:/home/hf/work/31155/my51-31155

into  mysql.com:/home/hf/work/31155/my50-31155

into  mysql.com:/home/hf/work/31155/my51-31155

into  gleb.loc:/home/uchum/work/bk/5.1-opt

into  gleb.loc:/home/uchum/work/bk/5.0-opt

into  mysql.com:/home/gluh/MySQL/Merge/5.1-opt

Bug#30982 CHAR(..USING..) can return a not-well-formed string
Bug#30986 Character set introducer followed by a HEX string can return bad result
check_well_formed_result moved to Item from Item_str_func
fixed Item_func_char::val_str for proper ucs symbols converting
added check for well formed strings for correct conversion of constants with underscore
charset

The special case with NULL as a regular expression
was handled at prepare time. But in this special case
the item was not marked as fixed. This caused an assertion
at execution time.
Fixed my marking the item as fixed even when known to 
return NULL at prepare time.

                  precision > 0 && scale <= precision'.

A sign of a resulting item of the IFNULL function was not
updated and the maximal length of this result was calculated
improperly. Correct algorithm was copy&pasted from the IF
function implementation.

into  mysql.com:/home/gluh/MySQL/Merge/5.1-opt

into  mysql.com:/home/gluh/MySQL/Merge/5.1-opt

into  mysql.com:/home/gluh/MySQL/Merge/5.0-opt

into  mysql.com:/home/gluh/MySQL/Merge/5.1-opt