Fix apparently-wrong code in table_multi_eq_selectivity().

Fix a trivial typo: in table_multi_eq_cond_selectivity(), reset the loop variable
between loops.

- Fix the crash, dont call from->type() at the start of the function
  because it might be unsafe.
- Unfortunately there is no testcase
- And this is also the reason we can't fix it properly (it should be
  safe to call from->type() here).

Second variant of the fix: reduce the scope of 'role' variable

Don't check the value of 'role' variable in the cases where we don't need it. (it 
may be marked as unitialized and we get a runtime error).

new fix

but keep the test case - it succeeds in 10.0 without the fix

and as a escape character when
SET NAMES xxx, character_set_connection=binary;
for cp932,big5,gbk,sjis

mysql-test/r/func_group.result:
  Test case
mysql-test/t/func_group.test:
  Test case
sql/item_sum.cc:
  Restore ORDER for prepared statements

Added comments
Ensure that tokudb test works even if jemalloc is not installed
Removed not referenced function Item::remove_fixed()

mysql-test/suite/rpl/t/rpl_gtid_reconnect.test:
  Fixed race condition
sql/item.cc:
  Indentation fix
sql/item.h:
  Removed not used function
  Added comment
sql/sql_select.cc:
  Fixed indentation
storage/tokudb/mysql-test/rpl/include/have_tokudb.opt:
  Ensure that tokudb test works even if jemalloc is not installed
storage/tokudb/mysql-test/tokudb/suite.opt:
  Ensure that tokudb test works even if jemalloc is not installed
storage/tokudb/mysql-test/tokudb_add_index/suite.opt:
  Ensure that tokudb test works even if jemalloc is not installed
storage/tokudb/mysql-test/tokudb_alter_table/suite.opt:
  Ensure that tokudb test works even if jemalloc is not installed
storage/tokudb/mysql-test/tokudb_bugs/suite.opt:
  Ensure that tokudb test works even if jemalloc is not installed
storage/tokudb/mysql-test/tokudb_mariadb/suite.opt:
  Ensure that tokudb test works even if jemalloc is not installed

sql/item.cc:
  don't forget to adjust the length of the string when removing leading spaces
sql/sql_acl.cc:
  when updating the hostname of the ACL_USER, update the hostname_length too
sql/sql_parse.cc:
  first compare the username string, then test the host pointer
  (host pointer is undefined when the username string is one of the hard-coded values
  set by the parser). This is not a bug, old code is perfectly safe as the undefined
  host pointer is never dereferenced, but let's keep valgrind happy.

don't kill statements in the default connection, kill them in a connection that
will be closed - it'll guarantee that `KILL con_id` will not apply to unrelated statements.

instead peek (maybe) old data.

We should assume that the store engine will report the first duplicate key for this case.

Old code of suppression of unsafe logging error with LIMIT didn't work, because of wrong usage of my_interval_timer().

Suppress unsafe logging errors to the error log if we get too many unsafe logging errors in a short time.
This is to not overflow the error log with meaningless errors.

- Each error code is suppressed and counted separately.
- We do a 5 minute suppression of new errors if we get more than 10 errors in that time.

Only print unsafe logging errors if log_warnings > 1.



mysql-test/suite/binlog/r/binlog_stm_unsafe_warning.result:
  Update test results as INSERT ... ON DUPLICATE KEY UPDATE doesn't get logged anymore
mysql-test/suite/binlog/r/binlog_unsafe.result:
  Update test results as INSERT ... ON DUPLICATE KEY UPDATE doesn't get logged anymore
mysql-test/suite/engines/README:
  Fixed typos
mysql-test/suite/rpl/r/rpl_known_bugs_detection.result:
  Update test results as INSERT ... ON DUPLICATE KEY UPDATE doesn't get logged anymore
sql/sql_base.cc:
  Don't log warning if there are two unique keys used with INSERT .. ON DUPLICATE KEY UPDATE.
  We should assume that the store engine will report the first duplicate key for this case.
sql/sql_class.cc:
  Suppress error in binary log if we get too many unsafe logging errors in a short time.
  Only print unsafe logging errors if log_warnings > 1

  - added more logic for ON DUPICATE KEY UPDATE upon Monty's request;
  - added an overlay for XtraDB

This was missing in my last commit for fixing possible lockups in SHOW STATUS.

sql/log.cc:
  Fixed comment
sql/sql_show.cc:
  Use LOCK_show_status when we add things to all_status_vars
sql/sql_test.cc:
  Remove not needed mutex_lock

and other fixes for gcc-4.9.1 on sid

have 0x5C as the second byte in a multi-byte character.
- Adding big5 tests covering an unassigned character 0xC840
  being stored into char/varchar/text/enum columns.