Added collection statistics for queries resolved via query cache.

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.

        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.

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.

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.

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.

allow user-defined EXECINFO_ROOT prefix, in case library and header are not placed under /usr/local . This change was requested by FreeBSD maintainer.

Other fix of maybe_null problem and revert of revno: 3608 "MDEV-3873 & MDEV-3876 & MDEV-3912 : Wrong result (extra rows) with ALL subquery from a MERGE view."

Bundled jemalloc can only be on  Linux and OSX without problems.
  
On BSDs, build fails because make does not understand GNU extensions (also BSDs do not need  jemalloc, it is already system malloc).
On Solaris, build fails with compile error.

- Better error message when using huge pages
- Fixed link error
- Test suite should run even on system with huge pages

storage/tokudb/ft-index/cmake_modules/TokuThirdParty.cmake:
  Fixed that linking works on systems that uses lib64
storage/tokudb/ft-index/portability/huge_page_detection.cc:
  Better error message
storage/tokudb/mysql-test/rpl/suite.pm:
  Test suite should run even on system with huge pages
storage/tokudb/mysql-test/tokudb/suite.pm:
  Test suite should run even on system with huge pages

Added --init-command argument to mysqlslap: SQL Command to execute
when connecting to MySQL server. Will automatically be re-executed
when reconnecting.

- The crash was caused because the optimizer called handler->multi_range_read_info()
  on a derived temporary table.  That table has been created, but not opened yet.
  Because of that, handler::table was NULL, which caused crash.
  Fixed by changing DS-MRR methods to use handler::table_share instead. 
  handler::table_share is set in handler ctor, so this should be safe.

read also [mariadb_safe] section.
modify the manpage accordingly (and remove a netware-specific option from it)

MDEV-5035 debian package conflict libmariadbclient18 5.5.33+maria-1~wheezy vs. mariadb-server-5.3 5.3.12-mariadb122~wheezy

Don't fail when an frm is inconsistent (legacy DB_TYPE_xxx code doesn't match the
engine name), use the engine name, ignore the legacy code.

don't set TABLE_SHARE::keys before TABLE_SHARE::key_info is set,
otherwise an error might leave only the first property set and it will
confuse TABLE_SHARE::destroy()

pending merges:
  Alexander Barkov 2013-09-16 backport from 10.0