Having galera-3 as a Depends stops installation of proceeding
on systems where package galera-3 is not available. The server
can run fine withouth galera enabled, therefore a more slack
relationship is more appropriate.

This is useful for developers who run autobake-deb.sh directly
from the source tree as the resulting source tar package will be
90% smaller and all operations regarding it consequently 10x faster.

 * dpatch cannot be removed yet, as packaging standard isn't updated
 * we don't want to remove libssl at all, as in upstream we rather
   use system provided OpenSSL than bundled, non-system updated and
   less commonly trusted YaSSL
 * keep versioned dependencies, they might prove helpful when building
   for multiple distros and releases

For tracking purposes this step is committed first before
the unnecessary dependencies are trimmed away.

libpcre3-dev (>= 2:8.35-3.2~) is however omitted (compared to
downstream Debian packaging) as it is not available in precise
and we don't want to break builds on precise yet.

 * README and NEWS are very old and mostly plain wrong and not needed
 * Lintian-overrides are relevant only in actual Debian QA systems
 * watch file was plain wrong and anyway relevant only in downstream distros

Use the slightly better Ubuntu version in both Ubuntu and
Debian and latest versions of Debian don't have problems
with AppArmor files included in packaging.

In non-wsrep builds, wsrep_running_threads should be defined to (0).

The version in sysvars_innodb,32bit,xtradb.rdiff was not updated

--gtid-ignore-duplicates was comparing sequence numbers as 32-bit, so
after 2**32 transactions things would start to fail.

The test did not wait until the server shuts down

Problem was that for queries of type:

select rand() r, rand()  p, rand() = rand() from a having r = p

The optimizer thought that r = p was same as rand() = rand() and this would always be true.

The problem was that when testing if two expressions are equal, we didn't take into account no determinstic functions.

The fix is to not compare non deterministic functions as equal.

Other things:
- Avoid calling init_and_set_log_file_name() when opening binary log.
- Remove newlines early when reading from index file.
- Ensure that reset_logs() will work even if thd is 0 (Can happen on startup)
- Added thd to sart_slave_threads() for better error handling.

Cleanups, fixed warnings from valgrind, fixed failing tests (because on changes in WSREP initialization)

This should not have caused any notable errors in most cases.

After fix, we are not using keys to solve MIN/MAX if the string used for comparision is longer thant the column-

Conflicts:
	sql/item_subselect.cc

Fixed also typo in comment

- Cache variables.lc_messages->errmsgs->errmsgs in variables.errmsgs

This gives us 15 byte less code space and 2 memory references for any access to language dependent message,
of which there are 500 in the server..

In some cases NO_ZERO_DATE did not allow datetime values with zero date part
and non-zero time part (e.g. '0000-00-00 10:20:30.123456').
Allowing values of this kind in all known pieces of the code.

Additional changes :
* On startup, do not initialize wsrep if wsrep_on=0.
* On shutdown, stop wsrep replication only if > 0 wsrep
threads are running.

- Renaming variables so that they don't shadow others (After this patch one can compile with -Wshadow and get much fewer warnings)
- Changed ER(ER_...) to ER_THD(thd, ER_...) when thd was known or if there was many calls to current_thd in the same function.
- Changed ER(ER_..) to ER_THD_OR_DEFAULT(current_thd, ER...) in some places where current_thd is not necessary defined.
- Removing calls to current_thd when we have access to thd

Part of this is optimization (not calling current_thd when not needed),
but part is bug fixing for error condition when current_thd is not defined
(For example on startup and end of mysqld)

Notable renames done as otherwise a lot of functions would have to be changed:
- In JOIN structure renamed:
   examined_rows -> join_examined_rows
   record_count -> join_record_count
- In Field, renamed new_field() to make_new_field()

Other things:
- Added DBUG_ASSERT(thd == tmp_thd) in Item_singlerow_subselect() just to be safe.
- Removed old 'tab' prefix in JOIN_TAB::save_explain_data() and use members directly
- Added 'thd' as argument to a few functions to avoid calling current_thd.

Fixing non-BMP characters to have the same weight, as it was before
MDEV-8418 and MDEV-8417.

MDEV-8418 utf16: compare broken bytes as "greater than any non-broken character"