Part IV: sql instrumentation

Subtraction of two unsigned months yielded a (very large) positive value.
Conversion of this to a signed value was not necessarily well defined.

Solution: do the subtraction on signed values.

eliminate 3 more "directory path" variables from the test's output (it was already
the case for other similar ones likes slow-query-log-file).

"set engine_condition_pushdown" is deprecated, engine condition pushdown is controlled
by a new "set optimizer_switch=engine_condition_pushdown=on|off".

fixing wrong indentation in two Makefile.am, which prevented the Anjuta IDE from parsing the MySQL tree.

           subquery in the select list
      
When a dependent subquery with count(distinct <col>) was 
evaluated multiple times, the Distinct_Aggregator was reused. 
However, the Aggregator was not reset, so when the subquery was
evaluated for the next record in the outer select, old dependent
info was used.
      
The fix is to clear() the existing aggregator in 
Item_sum::set_aggregator(). This ensures that the aggregator is
reevaluated with the new dependent information.

 
- backported code that handles %f/%g arguments in 
my_vsnprintf.c from 6.0 
- backported %f/%g tests in unittest/mysys/my_vsnprintf-t.c 
from 6.0 
- replaced snprintf("%g") in sql/set_var.cc with my_gcvt() 
- removed unnecessary "--replace-result"s for Windows in 
mysql-test/suite/sys_vars/t/long_query_time_basic.test 
- some test results adjustments

Backport Bug #43913  rpl_cross_version can't pass on conflicts complainig clash with --slave-load-tm

The 'rpl_cross_version' fails on mysql-next-mr-bugfixing as following:
mysqltest: In included file "./include/setup_fake_relay_log.inc": At line 80: query
'select './$_fake_filename-fake.000001\n' into dumpfile '$_fake_relay_index'' failed:
1290: The MySQL server is running with the --secure-file-priv option so it cannot execute
this statement.

To fix the problem by removeing the --secure-file-priv option
for adapting the update of the 'setup_fake_relay_log.inc'.

Unlike other platforms --mfpmath=sse is the default 
gcc mode on Mac OS X Intel. So it is unnecessary
to switch FPU to double precision mode (in fact,
it even breaks some math library functions).

Conflicts:
  - storage/myisam/mi_static.c

as the bug#46931 and bug#43913 have been closed.

corrected rotten test

backporting WL#2934.