- Backport into Maria DB 5.3, part 1

- Enable semi-join handling in the join cache code

- Fix valgrind failure
- Test result fixes (not finished)

There are still test failures because of:
- Wrong query results in outer join + semi join
- EXPLAIN output differences

- Do call update_used_tables() for new conditions obtained when adding
  outer join's triggered conditions. Correct values of used_tables() are
  now needed for condition pushdown.
- Update test results

mysql-test/suite/pbxt/r/join_outer.result:
  DS-MRR backport:
  - Update test results
sql/sql_select.cc:
  DS-MRR backport: fix buildbot valgrind failures:
  - Do call update_used_tables() for new conditions obtained when adding
    outer join's triggered conditions. Correct values of used_tables() are
    now needed for condition pushdown.

- Add opt_range_mrr.cc file into source repo

mysql-test/r/myisam_mrr.result:
  Make testcase work for both debug and release
mysql-test/t/myisam_mrr.test:
  Make testcase work for both debug and release
sql/Makefile.am:
  - Add opt_range_mrr.cc file into source repo

- Make index condition pushdown be controlled by an @@optimizer_switch flag,
  not by @@engine_condition_pushdown
- Make MRR buffer size be controlled by @@mrr_buffer_size, not 
  by @@read_rnd_buffer_size
- Move parts of code to separate files
- Code cleanup
- Add --sorted_result to some SELECTs in tests.

WL#2771 "Block Nested Loop Join and Batched Key Access Join"

- Fix PBXT test results (PBXT doesn't support MRR or ICP, but we get result 
  diffs because we've also backported a fix that
  - prints out "Using where" when the table has part of WHERE that it has 
    got from LEFT JOIN's ON expression
  - Does a better job at removing equalities that are guaranteed to be true 
    by use of ref acccess.

WL#2474 "Multi Range Read: Change the default MRR implementation to implement new MRR interface"
WL#2475 "Batched range read functions for MyISAM/InnoDb"
        "Index condition pushdown for MyISAM/InnoDB"
- Adjust test results (checked)
- Code cleanup.

WL#2474 "Multi Range Read: Change the default MRR implementation to implement new MRR interface"
WL#2475 "Batched range read functions for MyISAM/InnoDb"
        "Index condition pushdown for MyISAM/InnoDB"
- Fix valgrind failures

WL#2474 "Multi Range Read: Change the default MRR implementation to implement new MRR interface"
WL#2475 "Batched range read functions for MyISAM/InnoDb"
        "Index condition pushdown for MyISAM/InnoDB"
Igor's fix from sp1r-igor@olga.mysql.com-20080330055902-07614:
  There could be observed the following problems:
  1. EXPLAIN did not mention pushdown conditions from on expressions in the 
  'extra' column.  As a result if a query had no where conditions pushed 
  down to a table, but had on conditions pushed to this table the 'extra' 
  column in the EXPLAIN for the table missed 'using where'.
  2. Conditions for ref access were not eliminated from on expressions 
  though such conditions were eliminated from the where condition.

Some files are in different locations in this case.

- Merge to MariaDB 5.2

storage/federatedx/CMakeLists.txt:
  Add fedrated files for build

storage/federatedx/ha_federatedx.cc:
  lower_case_file_system do not suported for windows dll

storage/federatedx/CMakeLists.txt:
  removed the same goals for federated and federatedx

sql/sql_show.cc:
  Change decimal item to type holder, to be able to define the decimals and max_length for the DECIMAL
  field from the schema specification instead of the value of the item.

Fixed by renaming a file and editing the typo in Makefile.am

sql/mysqld.cc:
  Explicit type casting required by windows x64 compiler.
storage/xtradb/include/srv0srv.h:
  Parameters should be declared as ulong.
storage/xtradb/srv/srv0srv.c:
  Parameters should be declared as ulong.

Also missing copyright for copied macros.
Fix by Antony Curtis.