- CREATE PACKAGE [BODY] statements are now
  entirely written to mysql.proc with type='PACKAGE' and type='PACKAGE BODY'.
- CREATE PACKAGE BODY now supports IF NOT EXISTS
- DROP PACKAGE BODY now supports IF EXISTS
- CREATE OR REPLACE PACKAGE [BODY] is now supported
- CREATE PACKAGE [BODY] now support the DEFINER clause:

    CREATE DEFINER user@host PACKAGE pkg ... END;
    CREATE DEFINER user@host PACKAGE BODY pkg ... END;

- CREATE PACKAGE [BODY] now supports SQL SECURITY and COMMENT clauses, e.g.:

    CREATE PACKAGE p1 SQL SECURITY INVOKER COMMENT "comment" AS ... END;

- Package routines are now created from the package CREATE PACKAGE BODY
  statement and don't produce individual records in mysql.proc.

- CREATE PACKAGE BODY now supports package-wide variables.
  Package variables can be read and set inside package routines.
  Package variables are stored in a separate sp_rcontext,
  which is cached in THD on the first packate routine call.

- CREATE PACKAGE BODY now supports the initialization section.

- All public routines (i.e. declared in CREATE PACKAGE)
  must have implementations in CREATE PACKAGE BODY

- Only public package routines are available outside of the package

- {CREATE|DROP} PACKAGE [BODY] now respects CREATE ROUTINE and ALTER ROUTINE
  privileges

- "GRANT EXECUTE ON PACKAGE BODY pkg" is now supported

- SHOW CREATE PACKAGE [BODY] is now supported

- SHOW PACKAGE [BODY] STATUS is now supported

- CREATE and DROP for PACKAGE [BODY] now works for non-current databases

- mysqldump now supports packages

- "SHOW {PROCEDURE|FUNCTION) CODE pkg.routine" now works for package routines

- "SHOW PACKAGE BODY CODE pkg" now works (the package initialization section)

- A new package body level MDL was added

- Recursive calls for package procedures are now possible

- Routine forward declarations in CREATE PACKATE BODY are now supported.

- Package body variables now work as SP OUT parameters

- Package body variables now work as SELECT INTO targets

- Package body variables now support ROW, %ROWTYPE, %TYPE

MDEV-15405 Mixed replication fails with "Could not execute Delete_rows_v1 event" upon DELETE HISTORY

Allow slave thread to set time for system versioning

Note that every binlog event stores now(0), while microseconds
are only stored when they're actually used in the query.

Meaning for unversioned->versioned replication, there will be
no microseconds. Need to compensate for that.

Because NOW() is set to system time, unless overriden.
And both should follow big manual system time changes,
while still coping with lowres system clocks.

Ignoring system time changes is both confusing and
breaks with restarts.

as these fields are always declared NOT NULL anyway

MDEV-15395 Wrong result or Assertion `old_part_id == m_last_part' failed in ha_partition::update_row on slave

Revert commit fd240a10 and add a test case

set m_last_part to something meaningful when opening partitions

just as SHOW CREATE TABLE omits them from the index definition

copy the corresponding line from mysql_prepare_insert()

MDEV-15395 Wrong result or Assertion `old_part_id == m_last_part' failed in ha_partition::update_row on slave

RBR cannot work with system versioning on the master.

row_end column is either system time (not @@timestamp) with microsecond
precision or transaction id. Either way, it'll certainly be different
on the slave. So if the master row contains row_end column, it won't
match on the slave. And if we ignore row_end when comparing,
then some other row might match instead.

and few indentation changes

Remove 1668efb7 that introduced a special magic
behavior for UNIX_TIMESTAMP() in the AS OF context

and delete few garbage-in-garbage-out tests

Vers SQL: force VERS_ALTER_HISTORY_KEEP behavior in the slave thread

MDEV-15191 Assertion `bit < (map)->n_bits' failed in bitmap_is_set
upon INSERT

MDEV-15036 Assertion `!is_set() || (m_status == DA_OK_BULK
&& is_bulk_op())' in Diagnostics_area::set_ok_status or unexpected
ER_RANGE_NOT_INCREASING_ERROR

Vers_parse_info::fix_alter_info(): disallow DROP SYSTEM VERSIONING
for system_time partitioned tables.

add a test case

vers_insert_history_row(): do not insert rows with zero or negative lifetime.

mysql_update(): properly handle error from vers_insert_history_row()

Vers SQL: TRT fix getting TRX_ID by COMMIT_TS

Fixed wrong assumption that records are ordered by COMMIT_TS.
This is anyway a quick hack until tempesta-tech#314 is done.

See also FIXME and TODO in TR_table::query(MYSQL_TIME, bool).

Test: SEES case for trx_id.test [closes #456]

Lots of changes:
* calculate the current history partition in ::external_lock(),
  not in ::write_row() or ::update_row()
* remove dynamically collected per-partition row_end stats
* no full table scan in open_table_from_share to calculate these
  stats, no manual MDL/thr_locks in open_table_from_share
* no shared stats in TABLE_SHARE = no mutexes or condition waits when
  calculating current history partition
* always compare timestamps, don't convert them to MYSQL_TIME
  (avoid DST ambiguity, and it's faster too)
* correct interval handling, 1 month = 1 month, not 30 * 24 * 3600 seconds
* save/restore first partition start time, and count intervals from there
* only allow to drop first partitions if INTERVAL
* when adding new history partitions, split the data in the last history
  parition, if it was overflowed
* show partition boundaries in INFORMATION_SCHEMA.PARTITIONS

partition_info had a bunch of function pointers to avoid if()'s
when invoking part_type specific functionality (like get_part_id, etc).
But check_range_constants() and check_list_constants() were still
invoked conditionally, with if()'s.

Create partition_info::check_constants function pointer, get rid
of if()'s

Also remove alloc argument of check_range_constants(), added
in 26a3ff0a. Broken system versioning will be fixed in
following commits.

use include/have_xxx.inc when some feature needs to be present
(because --xxx in the opt file will fail if the xxx is not compiled in)

set variables in the test, not on the command line, to avoid unnecessary
server restarts (they're must slower than SET).

* TIMESTAMP precedence fixed.

Unit-based history point (vers_history_point_t; Vers_history_point).

Update partition stats on ha_partition::write_row()

SQL: DROP PERIOD FOR SYSTEM_TIME syntax

and remove ER_VERS_SYS_FIELD_EXISTS

originally by: Eugene Kosov