Introduce a new storage engine API method commit_checkpoint_request().
This is used to replace the fsync() at the end of every storage engine
commit with a single fsync() when a binlog is rotated.

Binlog rotation is now done during group commit instead of being
delayed until unlog(), removing some server stall and avoiding an
expensive lock/unlock of LOCK_log inside unlog().

Keep track of how many pending XIDs (transactions that are prepared in
storage engine and written into binlog, but not yet durably committed
on disk in the engine) there are in each binlog.

When the count of one binlog drops to zero, write a new binlog checkpoint
event, telling which is the oldest binlog with pending XIDs.

When doing XA recovery after a crash, check the last binlog checkpoint
event, and scan all binlog files from that point onwards for XIDs that
must be committed if found in prepared state inside engine.

Remove the code in binlog rotation that waits for all prepared XIDs to
be committed before writing a new binlog file (this is no longer necessary
when recovery can scan multiple binlog files).

MDEV-225: Replace with dummy events an event that is not understood by a slave to which it should be sent

Add function to replace arbitrary event with dummy event.

Add code which uses this to fix the bug that enabling row_annotate events
on the master breaks slaves which do not request such events.

Add that slaves set a variable @mariadb_slave_capability to inform the
master in a robust way about which events it can, and cannot, handle.

Add tests.

MDEV-457 Inconsistent data truncation on datetime values with fractional seconds represented as strings with no delimiters

New implementation for str_to_datetime. Fix MDEV-457 and related issues.

Switch automaticly to statement based replication for statements that can't generate row based events. This is needed to avoid getting
updates to system, statistics and admin tables logged to binary log.
- Removed special code used to temporarily change to statement based replication.
- Changed to a faster and smaller interface for temporarily switching to statement based replication.

sql/event_db_repository.cc:
  Change to new interface to not use row based replication for system table changes.
sql/events.cc:
  Change to new interface to not use row based replication for system table changes.
sql/sp.cc:
  Removed temporarily switching to statement based replication (this is now done automaticly in mysql_execute_command())
sql/sql_acl.cc:
  Change to new interface to not use row based replication for system table changes.
  Removed temporarily switching to statement based replication (this is now done automaticly in mysql_execute_command())
sql/sql_class.h:
  Added new interface for temporarily switching to statement based replication.
sql/sql_parse.cc:
  Mark commands that needs original replication mode with CF_FORCE_ORIGINAL_BINLOG_FORMAT.
  Switch automaticly to statement based replication for statements that can't generate row based events (and can't change replication mode)
sql/sql_udf.cc:
  Removed temporarily switching to statement based replication (this is now done automaticly in mysql_execute_command())

The task adds a more efficient handling of the queries with 
ORDER BY order LIMIT n, such that n is small enough and
no indexes are used for order.

Split ER_NO_SUCH_TABLE into ER_NO_SUCH_TABLE and ER_NO_SUCH_TABLE_IN_ENGINE to be able to distingus if a .frm file is missing or if the table is missing in the engine.


sql/handler.cc:
  Added ER_NO_SUCH_TABLE_IN_ENGINE
sql/rpl_record.cc:
  Fixed wrong printf
sql/share/errmsg-utf8.txt:
  Added ER_NO_SUCH_TABLE_IN_ENGINE
sql/sp.cc:
  Added ER_NO_SUCH_TABLE_IN_ENGINE
sql/sp_head.cc:
  Added ER_NO_SUCH_TABLE_IN_ENGINE
sql/sql_admin.cc:
  Added ER_NO_SUCH_TABLE_IN_ENGINE
sql/sql_base.cc:
  Added ER_NO_SUCH_TABLE_IN_ENGINE
sql/sql_show.cc:
  Added ER_NO_SUCH_TABLE_IN_ENGINE
sql/table.cc:
  Fixed typo

MDEV-405: Server crashes in test_if_skip_sort_order on EXPLAIN with GROUP BY and HAVING in EXISTS subquery
- Testcase

- Don't do early cleanup of uncorrelated subqueries if we're running an EXPLAIN.

        the fill_help_table-5.5.sql file was copied into mariadb.

per-file comments:
  scripts/fill_help_tables.sql
        MDEV-471 update help tables.

force -fno-strict-aliasing for oqgraph

The problem was that was_null and null_value variables was reset in each reexecution of IN subquery, but engine rerun only for non-constant subqueries.

Fixed checking constant in Item_equal sort.
Fix constant reporting in Item_subselect.

Various places in the server replication code was incorrectly quoting
strings, which could lead to incorrect SQL on the slave/mysqlbinlog.

fix mysys/waiting_threads.c to compile w/o performance schema
include clients. scripts and manpages in -DWITHOUT_SERVER

only add cmake as a build dependency for distributions, where cmake is recent enough

Item::get_date() should return 1 unless the value is a valid date.