refining the regression test to avoid explicit innodb engine in create.

Problem 1: BUG#36625: rpl_redirect doesn't do anything useful. It tests an
obsolete feature that was never fully implemented.
Fix 1: Remove rpl_redirect.
Problem 2: rpl_innodb_bug28430 and rpl_flushlog_loop are disabled despite the
bugs for which they were disabled have been fixed.
Fix 2: Re-enable rpl_innodb_bug28430 and rpl_flushlog_loop.

The convert_constant_item function converts a constant to integer using
field for condition like 'field = a_constant'. In some cases the
convert_constant_item is called for a subquery when outer select is already
being executed, so convert_constant_item saves field's value to prevent its
corruption. For EXPLAIN and at the prepare phase field's value isn't
initialized yet, thus when convert_constant_item tries to restore saved
value it fails assertion.

Now the convert_constant_item doesn't save/restore field's value if it's
haven't been read yet. Outer constant values are always saved.

order by

Problem was that the first index read was unordered,
and the next was ordered, resulting in use of
uninitialized data.

Solution was to use the correct variable to see if
the 'next' call should be ordered or not.

  Bug#39848 events_bugs fails sporadically on pushbuild
            (missing rows in table event_log)
     Details: Reimplement the subtest for BUG 28924
              - check if the number of rows within the table
                event_log changes but don't print rows
                because the number varies depending on
                load on testing box
              - shift DROP USER befor DROP EVENT
                = Subtest fits again to old bug
              - remove no more needed comments + variables
  Bug#39863 events_bugs fails sporadically on pushbuild 
            (extra processes in I_S.PROCESSLIST)
     Details: Abort with appropriate message to the protocol if
              release_lock() does not has the intended effect.
              This cannot prevent problems caused by the probably
              buggy release_lock() but it reveals if we had a
              problem in this area.
  Bug#39978 main.events_bugs does not clean up
     Detail: Restore global.event_scheduler = ON at end of test
  Bug#39569 events_bugs fails sporadically on pushbuild
            (should have failed with errno 1539)
     Detail: Set $wait_timeout to 4 instead of 2
- Fix two instabilities (result sets pulled from processlist in
  subtest for bug 16407) which were found during tests with high
  parallel I/O load
- Minor improvements of formatting
  Details:
  - Add comments
  - Remove tabs and trailing blanks
  - Add line breaks for better readability

updating two test results.

correct text describing the --plugin-load option to mysqld

The partitioning clause is only a very long single line, which is very
hard to interpret for a human. This patch breaks the partitioning
syntax into one line for the partitioning type, and one line per
partition/subpartition.

Adding missing drop of created table and tidying display.

TRUNCATE TABLE for InnoDB tables returned a count showing an approximation
of the number of rows affected to gain efficiency.
Now the statement always returns 0 rows affected for clarity.

      
When statement-based replication is used, and the
transaction isolation level is READ-COMMITTED or stricter,
InnoDB will print an error because statement-based
replication might lead to inconsistency between master
and slave databases. However, when the binary log is not
engaged, this is not an issue and an error should
not be printed.

This patch makes thd_binlog_format() return BINLOG_FORMAT_
UNSPEC when the binary log is not engaged for the given
thread.

a test on the bug page does not reveal the problem with the latest trees.

Adding the test to the rpl suite in order to monitor regression.

implicit command which isn't completed immediately.