MDEV-4102 Limitation on DOUBLE or REAL length is ignored with INSERT .. SELECT

* Maintain coding style in sql_yacc.yy in regards to optional clauses.
* Remove unused variable from sql_acl.cc.
* Update test case

Update test to account for the new SHOW CREATE USER command.

Adding an extra statement requires test cases update.

Implemented the alter user syntax. Also tested that create user
creates users accordingly.

Extend the syntax accepted by the grammar to account for the new create user
and alter user syntax.

Simplified audit event dispatching call chain from:
  mysql_audit_notify_connection_connect() // can be inlined
  mysql_audit_notify()                    // can't be inlined
  connection_class_handler()              // can't be inlined
  event_class_dispatch()                  // can be inlined
  plugins_dispatch()                      // can be inlined
  plugin->event_notify()                  // can't be inlined
to:
  mysql_audit_notify_connection_connect() // can be inlined
  mysql_audit_notify()                    // can't be inlined
  plugins_dispatch()                      // can be inlined
  plugin->event_notify()                  // can't be inlined

In RHEL7/RHEL7.1 libcrack behavior seem to have been modified so that
"foobar" password is considered bad (due to descending "ba") earlier than
expected. For details google for cracklib-2.9.0-simplistic.patch.

Adjusted affected passwords not to have descending and ascending sequences.

Show outer_ref_condition in EXPLAIN FORMAT=JSON output.

Also fixed race condition in main.connect2 test: we need to wait for
disconnected connections to actually decrease Threads_connected.

This is expected to fix many test failures on 32bit builds where creation of
second temporary table was failing.

        --raw, --stop-never and --stop-never-slave-server-id=id options
        added to the mysqlbinlog tool.

This is an addition to rev. ed990465
Reverted some test cases changes done in MDEV-6150.

Cleanup now unused arguments of tdc_open_view().

Remove tdc_acquire_share() helpers: they don't actually make things simpler.

tdc_assign_new_table_id() does not relate to table cache, move it out of
table_cache.cc.

Compile time assertion "sizeof(struct st_irem) % sizeof(double) == 0" started
to fail on 32bit systems after my_thread_id was changed from ulong to int64.

Fixed by added padding to struct st_irem on 32bit systems.

First thread was getting id 0, while it is intended to get id 1.

Fixed assertion failure introduced along with MDEV-6150 (thd must be unlinked
before calling "delete thd").

It is not permitted to "delete thd" under LOCK_thread_count anymore.

Also, renamed wsrep_skip_append_keys to wsrep_ignore_table.
Test case : galera.galera_as_slave_gtid.test

- "Early NULLs filtering" optimization used to "peel off" Item_ref and
  Item_direct_ref wrappers from an outside column reference before
  adding "outer_table_col IS NOT NULL" into JOIN::outer_ref_cond.
- When this happened in a subquery that was evaluated in a post-GROUP-BY
  context, attempt to evaluate JOIN::outer_ref_cond would fetch an
  incorrect value of outer_table_col.

10.0 merge
10.0-galera merge
connect/10.1 merge

contains broken procedure body when used shielding quotes inside.

  If any given variable the xtrabackup-v2 sst script looks for is specified
  multiple times in cnf file then it tend to pick both of them causing
  some of the follow-up command to fail.

  Avoid this programatic mistake by honoring only the last variable assigned
  setting as done by mysqld too.

  Check https://bugs.launchpad.net/percona-xtradb-cluster/+bug/1362830