Bug #15684: @@version_* are not all SELECTable

  Added the appropriate information as read-only system variables, and
  also removed some special-case handling of @@version along the way.

  @@version_bdb was added, but isn't included in the test because it
  depends on the presence of BDB.

into  mysql.com:/home/jimw/my/mysql-5.0-clean

into  mysql.com:/home/stewart/Documents/MySQL/5.0/merge

into  mysql.com:/home/stewart/Documents/MySQL/5.0/merge

into  zippy.(none):/home/cmiller/work/mysql/mysql-5.0__ready

into  zippy.(none):/home/cmiller/work/mysql/mysql-5.0__ready

  Testsuite added

  5.0 additional fix for b#18691
  Handle DECIMAL the same with INT and REAL.

into  mysql.com:/usr/home/bar/mysql-5.0

does not have "NOT NULL" attribute set.  Also, calculate the padding
characters more safely, so that a negative number doesn't cause it to 
print MAXINT-n spaces.

into  april.(none):/home/svoj/devel/mysql/BUG17917/mysql-5.0

removing comments from the opt file.

into  mysql.com:/usr/home/bar/mysql-4.1.b18691

into  sanja.is.com.ua:/home/bell/mysql/bk/work-5.0

into  mysql.com:/opt/local/work/mysql-5.0-runtime-merge

into  sanja.is.com.ua:/home/bell/mysql/bk/work-5.0

into  mysql.com:/opt/local/work/mysql-5.0-runtime-merge

into  dl145j.mysql.com:/tmp/andrei/5.0-bug18715_drop_view_slave

into  sanja.is.com.ua:/home/bell/mysql/bk/work-5.0

into  sanja.is.com.ua:/home/bell/mysql/bk/work-5.0

into  mysql.com:/home/MySQL/5.0-Bug-17248a

into  mysql.com:/home/psergey/mysql-5.0-csc9139

get_best_covering_ror_intersect() was copying ror_scans starting from the 
end of the array and not from its beginning.

into  april.(none):/home/svoj/devel/mysql/BUG17917/mysql-4.1

into  april.(none):/home/svoj/devel/mysql/BUG17917/mysql-4.1

Retrieving data from compressed MyISAM table which is bigger than 4G on 32-bit box
with mmap() support results in server crash.

mmap() accepts length of bytes to be mapped in second param, which is 32-bit
size_t. But we pass data_file_length, which is 64-bit my_off_t. As a result only
first data_file_length % 4G were mapped.

This fix adds additional condition for mmap() usage, that is use mmap() for
compressed table which size is no more than 4G on 32-bit platform.

Conversion from int and real numbers to UCS2 didn't work fine: 
CONVERT(100, CHAR(50) UNICODE)
CONVERT(103.9, CHAR(50) UNICODE)

The problem appeared because numbers have binary charset, so,
simple charset recast binary->ucs2 was performed
instead of real conversion.

Fixed to make numbers pretend to be non-binary.

into  rurik.mysql.com:/home/igor/dev/mysql-5.0-0

limit.

into  mysql.com:/home/tomash/src/mysql_ab/mysql-5.0-bug15933

CONNECTION_ID() was implemented as a constant Item, i.e. an instance of
Item_static_int_func class holding value computed at creation time.
Since Items are created on parsing, and trigger statements are parsed
on table open, the first connection to open a particular table would
effectively set its own CONNECTION_ID() inside trigger statements for
that table.

Re-implement CONNECTION_ID() as a class derived from Item_int_func, and
compute connection_id on every call to fix_fields().

into  mysql.com:/opt/local/work/mysql-5.0-merge

into  mysql.com:/home/tomash/src/mysql_ab/mysql-5.0-bug15933

a race between updating and checking Max_used_connections.  This is done in
a loop until either disconnect finished or timeout expired.  In a latter case
the test will fail.

Fixed in parser. rpl_view gained no changes but rpl_view-slave.opt.