The bug could cause a crash when several connections needed
persistent statistics for the same table.

Also added a missing call of set_statistics_for_table() in the code
of the function mysql_update.

Backport the fix from 10.0 tree

- The problem was that thd_killed() may be called by innodb from 
  an internal innodb thread.
- Fixed by not processing APC requests when we're not in the thread
  that owns the APC target.

Field matching fixed.
DBUG_ASSERT fixed.

Made allocation of memory for statistical data in a table share to be thread safe.
This memory is now allocated in a special MEM_ROOT that is created for each
table share.  

Remove timed mutexes in XtraDB - obsolete feature that does not link on Windows, if plugin is build dynamically
It was already  removed from innobase in the past.

Reasons:
  - as of 5.5.27, YEAR(2) is deprecated, hence the new warning;
  - MDEV-553 - different error code/message on out-of-range autoincrement;
  - INSERT IGNORE now produces a warning if a duplicate was encountered

storage_engine tests and upstream engines/* suites went out of sync with current MariaDB code. Reasons:
  - as of 5.5.27, YEAR(2) is deprecated, hence the new warning;
  - MDEV-553 - different error code/message on out-of-range autoincrement;
  - INSERT IGNORE now produces a warning if a duplicate was encountered (change pushed along with MDEV-553)

- update ha_cassandra::start_bulk_insert() definition to match those in class handler.

The patch lifts the limitation of the current implementation
of ALTER TABLE that does not allow to build unique/primary
indexes by sort for MyISAM and Aria engines.

- Cleanup ha_cassandra::store_lock()
- Remove dummy ha_cassandra::delete_table()
- Add HA_TABLE_SCAN_ON_INDEX to table_flags()

- Register counters directly in the array passed to maria_declare_plugin. As 
  a consequence, FLUSH TABLES will reset the counters.
- Update test results accordingly.

- Partially address review feedback.
- Update cassandra.test result result
- make cassandra.test timezone-agnostic

Implement it in a different way that works on both release and debug
builds, and still uses --skip instead of --require.

have_openssl variable was ON even when OpenSSL was not used (but YaSSL was).
fix that, so that have_openssl really corresponds to OpenSSL

rename not_openssl.inc to not_ssl.inc and fix the test accordingly.

remove unused require files

MDEV-438 Microseconds: Precision is ignored in CURRENT_TIMESTAMP(N) when it is given as a default column value

For MySQL 5.6 compatibility, support precision specification in CURRENT_TIMESTAMP in
a default clause, when it's not less than the column's precision.

With MDEV-532, the binlog_checkpoint event is logged asynchronously
from a binlog background thread. This causes some sporadic failures
in some test cases whose output depends on order of events in
binlog.

Fix using an include file that waits until the binlog checkpoint
event has been logged before proceeding with the test case.