Introduced double precision height-balanced histograms.

One of them is quite serious: the function table_cond_selectivity used
the TABLE_REF structure for ref/eq_ref access methods as if they had been
filled. In  fact these structure are filled after the best execution plan
has been chosen.

The other bugs happened due to:
- an erroneous attempt at get statistics on the result of materialization
  of a view
- incorrect handling of ranges with no left/right limits when calculating
  selectivity of range conditions on non-indexed columns
- lack of cleanup for some newly introduced fields
 

of the table conditions. 

pushed down condtions. 

mysql-test/suite/heap/heap.result:
  Added test case
mysql-test/suite/heap/heap.test:
  Added test case
storage/heap/hp_delete.c:
  Fixed that we don't change order of keys for the current key when we delete them from the hash table.
  Fixed that 'current_hash_ptr' is correct after heap_delete_key().
  Don't "reset current_hash_ptr" on delete; This will improve time a lot for delete of rows when not all rows matches the search criteria.

  committer: Sergei Golubchik <sergii@pisem.net> 
    fix for a valgrind builds. 
    my_alloca() cannot have MY_THREAD_SPECIFIC, because can be used 
    outside of the THD context. 

MDEV-537 Make multi-column non-top level subqueries to be executed via index (index/unique subquery)
           instead of single_select_engine

This task changes the IN-EXISTS rewrite for multi-column subqueries
"(a, b) IN (select b, c ...)" to work in the same way as for
single-column subqueries "a IN (select b ...) with respect to the
injection of NULL-rejecting predicates.
 
More specifically, the method
Item_in_subselect::create_row_in_to_exists_cond()
adds Item_is_not_null_test and Item_func_trig_cond only if the left
IN operand can be NULL. Not having these predicates when not necessary,
makes it possible to rewrite the subquery into a "unique_subquery" or
"index_subquery" when there is a suitable index on the only
subquery table.

otherwise safemalloc and my_malloc_size_cb_func will use
current_thd before it's defined

Add a wait for binlog checkpoint to avoid thread scheduling
giving different binlog order at random.

When CHANGE MASTER fails, it may or may not have already added
the Master_info * to the index. Implement logic that properly
handles removal and freeing in both cases.

to storage/cassandra/CMakeLists.txt

storage/cassandra/CMakeLists.txt:
  more thourough CHECK_CXX_SOURCE_COMPILES test, that checks whether
  boost::shared_ptr can work with --fno-rtti
  
  don't install anything in INSTALL_SYSCONFDIR, if the latter is unset

from MariaDB 10.0.
  
The bug in mdev-3948 was an instance of the problem fixed by Sergey's patch
in 10.0 - namely that the range optimizer could change table->[read | write]_set,
and not restore it.
  
revno: 3471
committer: Sergey Petrunya <psergey@askmonty.org>
branch nick: 10.0-serg-fix-imerge
timestamp: Sat 2012-11-03 12:24:36 +0400
message:
  # MDEV-3817: Wrong result with index_merge+index_merge_intersection, InnoDB table, join, AND and OR conditions
  Reconcile the fixes from:
  #
  # guilhem.bichot@oracle.com-20110805143029-ywrzuz15uzgontr0
  # Fix for BUG#12698916 - "JOIN QUERY GIVES WRONG RESULT AT 2ND EXEC. OR
  # AFTER FLUSH TABLES [-INT VS NULL]"
  #
  # guilhem.bichot@oracle.com-20111209150650-tzx3ldzxe1yfwji6
  # Fix for BUG#12912171 - ASSERTION FAILED: QUICK->HEAD->READ_SET == SAVE_READ_SET
  # and
  #
  and related fixes from: BUG#1006164, MDEV-376:
  
  Now, ROR-merged QUICK_RANGE_SELECT objects make no assumptions about the values
  of table->read_set and table->write_set.
  Each QUICK_ROR_SELECT has (and had before) its own column bitmap, but now, all 
  QUICK_ROR_SELECT's functions that care: reset(), init_ror_merged_scan(), and 
  get_next()  will set table->read_set when invoked and restore it back to what 
  it was before the call before they return.

  This allows to avoid the mess when somebody else modifies table->read_set for 
  some reason.

MDEV-3875 Wrong result (missing row) on a DISTINCT query with the same subquery in the SELECT list and GROUP BY

fix remove_dup_with_hash_index() and remove_dup_with_compare() to take NULLs into account

The problem was that a temporary table was re-created as a non-temporary table.


mysql-test/suite/maria/truncate.result:
  Added test cases
mysql-test/suite/maria/truncate.test:
  Added test cases
sql/sql_truncate.cc:
  Mark that table to be created is a temporary table
storage/maria/ha_maria.cc:
  Ensure that temporary tables are not transactional.

Miscellaneous workarounds for  drop-in compatibility problems with Linux distributions, arounf versioning of the 
MySQL 5.5 client shared library. There seems to be 3 different ways major distributions handle versioning

1. Fedora  (also Mageia, and likely  other Redhat descendants) way 
   old, 5.1 API functions are given version libmysqlclient_16
   new API functions  (client plugins, mysql_stmt_next ) are given version libmysqlclient_18
   some extra functions beyond API are exported.
   some functions are renamed.

2.Debian Wheezy way 
  all functions are given libmysqlclient_18 version

3. Ubuntu  way (or MySQL/MariaDB download packages)
  no versioning

UIp to this fix, MariaDB distributions did not have any versioning in the libraries, this rendered client library incompatible to distributions 
thus exchanging  distribution's libmysqlclient.so.18.0.0  with MariaDB's did not work nicely (anywhere but on Ubuntu)


THE FIX  
is to build libraries the same way as distributions do it 
- when building RPMs, use  same version script as Fedora does, Make sure to export extra-symbols, the same as Fedora exports.
- when building DEBs, use the same version script as Debian Wheezy
- do not use version scripts otherwise


Also, makes sure that extensions of  MySQL APIs (asynchronous client functionality) is exported by  the shared libraries.