The patch for bug mdev-5105 incorrectly counted conditions in nested joins.

        The emb_free_embedded_thd() has the thread-unsafe code
        so should be 'mutexed' also.

When we open merge children open error is normally handled early during
open phase. But there are two exceptions when error is handled later during
attach phase: CHECK/REPAIR TABLE and tables added by the pre-locking code.

The latter case wasn't considered by assertion in the merge code. This
assertion is corrected. Note that in MySQL-5.6 this assertion is removed.

        LOCK_thread_count locked when we do threads.append().

Objects of the classes Item_func_isnull and Item_func_isnotnull
must have the flag sargable set to TRUE.
Set the value of the flag sargable only in constructors of the 
classes inherited from Item_int_func.

Make IO thread check for end of event group, so that upon
disconnect at the end of an event group it can report the last
read GTID as expected. Also inject a fake Rotate event at
reconnect when skipping part of an initial event group, to
give SQL thread the correct Read_Master_Log_Pos.

Reported by Pavel Ivanov.

Mark a few PCRE CMake variables as advanced,
so the are not presented in cmake-gui by default.

The bug caused a memory overwrite in the function update_ref_and_keys()
It happened due to a wrong value of SELECT_LEX::cond_count. This value
historically was calculated by the fix_fields method. Now the logic of
calling this method became too complicated and, as a result, this value
is calculated not always correctly.
The patch changes the way how and when  the values of SELECT_LEX::cond_count
and of SELECT_LEX::between_count are calculated. The new code does it just at
the beginning of update_ref_and_keys().
 

        Additional patch for the 5.5.

        The Gis_point::init_from_wkt called the String::realloc(),
        and this call is quite slow in the DEBUG mode. Which makes
        loading the huge polygon hang forever.
        Fixed by using the String::realloc(size, inc_size) version instead
        as it's done for other spatial features.

Do not pass PCRE_UCP flag for binary data.
This makes bytes 0x80..FF not to belong to 
generic character classes \d (digit) and \w (word character).

SELECT 0xFF RLIKE '\\w';
 -> 0

Note, this change does not affect non-binary data,
which is still examined with the PCRE_UCP flag by default.

For aggregated fields from views/derived tables the possible adjustment
of thd->lex->in_sum_func->max_arg_level in the function Item_field::fix_fields
must be done before we leave the function.

Fixing compilation failure on Solaris.
The int64_t type was not defined because stdint.h was not included
due to a missing definition in pcre/config-cmake.h.in.

Clean-up: moving initialization of my_string_stack_guard
and pcre_stack_guard into init_libstrings() and init_pcre().

Adding tests with 0x00 characters from

Bug#70470 REGEXP fails to find matches after NUL character

Adding more tests for case sensitivity,
with various collation and (?i) flags combinations.

PCRE unit tests failed on Ubuntu Precise, because "source" 
is not a known command in "dash" (the default shell in Precise).

Changing "source" to ".", which should be understood in all shells.

Apparently in a general case a short-cut for the distinct optimization
is invalid if join buffers are used to join tables after the tables whose
values are to selected.

MDEV-4425 Regexp enhancements
Adding ${CMAKE_BINARY_DIR}/pcre into search path for *.h files.
Needed for find pcre.h (which is generated from pcre.h.in) when
build directory != source directory.

Merging the following MySQL-5.6 changes:
- WL#5624: Collation customization improvements
  http://dev.mysql.com/worklog/task/?id=5624

- WL#4013: Unicode german2 collation
  http://dev.mysql.com/worklog/task/?id=4013

- Bug#62429 XML: ExtractValue, UpdateXML max arg length 127 chars
  http://bugs.mysql.com/bug.php?id=62429
  (required by WL#5624)

Adding ${CMAKE_BINARY_DIR}/pcre into search path for *.h files.
Needed for find pcre.h (which is generated from pcre.h.in) when
build directory != source directory.

Adding pcre_stack_guard to avoid crashes in pcre_compile()
on a long recursive patterns with parenthesizes:

SELECT a RLIKE '((((...((((x)))...))))';

Removing pcre.h from the tree, it's generated from pcre.h.in 

- Commenting out unused instructions in pcre/CMakeLists.txt
- Don't print PCRE configuration status by default.

This patch also makes libstrings use my_malloc() and my_free()
in embedded server. Previously, embeddes server used malloc()
and free() in libstrings.

Analysis: There is debug assertion ut_ad(trx->start_file != 0); and ut_ad(trx->start_line != 0); on trx_start_low funcition at trx0trx.cc. These fields are initialized on include/trx0trx.h at function trx_start_if_not_started_xa. Thus at trx_prepare_for_mysql function should call trx_start_if_not_started_xa(trx); not trx_start_if_not_started_xa_low(trx) directly;

It seems to compile/work fine with CMake-2.6.

to avoid system *.h files to be included (e.g. like on labrador).

a special handling.