MDEV-7936: Assertion `!table || table->in_use == _current_thd()' failed on parallel replication in optimistic mode

Additional 10.1-specific test case.

MDEV-7936: Assertion `!table || table->in_use == _current_thd()' failed on parallel replication in optimistic mode

Make sure that in parallel replication, we execute wait_for_prior_commit()
before setting table->in_use for a temporary table. Otherwise we can end up
with two parallel replication worker threads competing with each other for
use of a temporary table.

Re-factor the use of find_temporary_table() to be able to handle errors
in the caller (as wait_for_prior_commit() can return error in case of
deadlock kill).

MDEV-7668: Intermediate master groups CREATE TEMPORARY with INSERT, causing parallel replication failure

[This commit cherry-picked to be able to merge MDEV-7936, of which it
is a pre-requisite, into both 10.0 and 10.1.]

Parallel replication depends on locking (table locks, row locks, etc.) to
prevent two conflicting transactions from running and committing in parallel.
But temporary tables are designed to be visible only to one thread, and have
no such locking.

In the concrete issue, an intermediate master could commit a CREATE TEMPORARY
TABLE in the same group commit as in INSERT into that table. Thus, a
lower-level master could attempt to run them in parallel and get an error.

More generally, we need protection from parallel replication trying to run
transactions in parallel that access a common temporary table.

This patch simply causes use of a temporary table from parallel replication
to wait for all previous transactions to commit, serialising the replication
at that point.

(A more fine-grained locking could be added later, possibly. However,
using temporary tables in statement-based replication is in any case
normally undesirable; for example a restart of the server will lose
temporary tables and can break replication).

Note that row-based replication is not affected, as it does not do any
temporary tables on the slave-side.

This patch also cleans up the locking around protecting the list of
temporary tables in Relay_log_info. This used to take the
rli->data_lock at the end of every statement, which is very bad for
concurrency. With this patch, the lock is not taken unless temporary
tables (with statement-based binlogging) are in use on the slave.

Fix EXPLAIN FORMAT=JSON to produce output that's not worse than
the tabular form.

Provide basic info about sorting/grouping done by the queries.

report when a pattern is found
do not abort, but merely report when a pattern is not found

that is, after

  commit dd8f9319
  Author: Sergei Golubchik <serg@mariadb.org>
  Date:   Fri Apr 10 02:36:54 2015 +0200

    be less annoying about sysvar-based table attributes
    do not *always* add them to the create table definition,
    but only when a sysvar value is different from a default.
    also, when adding them - don't quote numbers

dereferencing of the uninitialized pointer bpade->slot
(when compiled without UNIV_DEBUG)

MDEV-7816 ALTER with DROP INDEX and ADD INDEX .. COMMENT='comment2' ignores the new comment

If a flag is supported only for C or C++ - add it to the
corresponding compiler option list. Old behavior was to
add always to both, but only if supported in both.

unportable, use grep

that for some reasons worked on linux, but crashed on windows

this will prevent user from creating tables with ENCRYPTED=OFF

because one is supposed always to use it with innodb-encrypt-tables

and make it a session variable, not global, as any decent
default sysvar for a table attribute should be

instead of manually implenting "default from a sysvar" in the code

do not *always* add them to the create table definition,
but only when a sysvar value is different from a default.

also, when adding them - don't quote numbers

fix sys_var->is_default() method (that was using default_val property
in a global sys_var object to track per-session state):
* move timestamp to a dedicated Sys_var_timestamp class
  (in fact, rename Sys_var_session_special_double to Sys_var_timestamp)
* make session_is_default a virtual method with a special implementation
  for timestamps
* other variables don't have a special behavior for default values
  and can have session_is_default() to be always false.

which is separate from the encryption key version

With changes:

* update tests to pass (new encryption/encryption_key_id syntax).
* not merged the code that makes engine aware of the encryption mode
  (CRYPT_SCHEME_1_CBC, CRYPT_SCHEME_1_CTR, storing it on disk, etc),
  because now the encryption plugin is handling it.
* compression+encryption did not work in either branch before the
  merge - and it does not work after the merge. it might be more
  broken after the merge though - some of that code was not merged.
* page checksumming code was not moved (moving of page checksumming
  from fil_space_encrypt() to fil_space_decrypt was not merged).
* restored deleted lines in buf_page_get_frame(), otherwise
  innodb_scrub test failed.

It used to double-encrypt it, relying on the fact that second
encrypt() call was (like XOR) negating the effect of the
first one.

because of encryption changes - make it beta and let
it mature together with the server

rename to innodb-debug-force-scrubbing