Removed const declarations to get rid of compiler warnings. The changes are similar to what is done in innobase in MySQL 5.5

BUILD/SETUP.sh:
  By default, build also with innodb-plugin
mysql-test/mysql-test-run.pl:
  Also search in lib64 directory for plugins (This is used at least on OpenSuse 12.1 when using default build scripts)
mysql-test/r/lock_multi.result:
  Allow test to be re-run even if it crashed.
mysql-test/t/lock_multi.test:
  Allow test to be re-run even if it crashed.
scripts/make_binary_distribution.sh:
  Ensure that libexecdir is named libexec (was not on OpenSuse 12.1)
scripts/mysql_config.sh:
  Fixed detection of lib64 was used.

This also fixes a (not likely) crashing bug when forcing a thread that was doing a table lock to re-open it's files, for example by creating a trigger.


mysys/thr_lock.c:
  Added more checking to find wrong locks.
  Removed one, not needed, parameter to thr_lock
sql/lock.cc:
  Fixed mysql_lock_tables() to retry with new sql_lock if lock fails. This was needed as table may be closed and reopened between retry's and then the old sql_lock will point to stale data.
sql/mysql_priv.h:
  Updated prototype
sql/sql_base.cc:
  Ensure that all tables are closed if opening of system table failes; This fixes the assert in THD::restore_backup_open_tables_state
sql/sql_handler.cc:
  Updated variable type

 execution which mtr --embedded does not support

Sort counters by their names (otherwise, the order of SHOW STATUS output is sometimes sorted and sometimes not)

 Handler_mrr_key_refills, Handler_mrr_rowid_refills.

UNIX_TIMESTAMP() can be null, and returns null for invalid values

Fixed compiler warnings found by buildbot

Makefile.am:
  Removed extra empty line
cmd-line-utils/libedit/sys.h:
  Fixed that strndup() doesn't give compiler warnings
mysql-test/Makefile.am:
  Fixes for 'make distcheck'
plugin/auth_pam/auth_pam.c:
  Ensure that prototype for strndup() is included on linux
sql/share/Makefile.am:
  Fixes for 'make distcheck'
storage/innodb_plugin/btr/btr0sea.c:
  Fixed compiler warning
support-files/Makefile.am:
  Fixes for 'make distcheck'

mysql-test/suite/innodb_plugin/t/innodb_gis.test:
  Don't run test if innodb_plugin isn't used.

sql/signal_handler.cc:
  Added missing signal values.

Fixed supression in mysql-test-run so it also works on windows.

mysql-test/mysql-test-run.pl:
  Fixed supression so it also works on windows.
mysql-test/valgrind.supp:
  More general handling of memory loss in dlclose (backported from 5.2)
sql/signal_handler.cc:
  Added newlines around link to how to do bug reports

"relocation R_X86_64_PC32 against `handler_index_cond_check' can not be used when making a shared object; recompile with -fPIC"
don't use visibility=hidden for external functions

"safe exception patch".
Remove misleading comments suggesting about signal() Windows, the routine here
is part of a exception handler, and sig parameter is an exception code.

- In mi_rkey(), do correct handling of case where mi_yield_and_check_if_killed() 
  detects that the thread was killed (all other similar functions in MyISAM/Aria have 
  slightly different code and do not have this problem).
- Also fixed assignment in DBUG_ASSERT
- this is 2nd variant of the fix:
   = make .result file smaller
   = run KILLable statements in a separate connection, otherwise we could end up trying to 
     KILL the final "DROP TABLE" statement

mysql-test/suite/innodb/t/innodb_bug51920.test:
  Add another possible connect error

Fixed README with link to source
Merged InnoDB change to XtraDB

README:
  Added information of where to find MariaDB code
storage/archive/ha_archive.cc:
  Removed memset() of rows, a MariaDB checksum's doesn't touch not used data.

This happend when you have more than 1024 open Aria tables during checkpoint.


mysql-test/mysql-test-run.pl:
  Fixed that variable names are consistent between external and internal server.
mysql-test/suite/maria/suite.pm:
  Test for aria-block-size instead of 'aria' as 'aria' is not set for embedded server.
  This should be ok for aria tests, as aria is never disabled for these.
storage/maria/ma_checkpoint.c:
  Fixed bug when there are more than 1024 open Aria tables during checkpoint.

BUG#933407: Valgrind warnings in mark_as_null_row with materialization+semijoin, STRAIGHT_JOIN, impossible WHERE
- In return_zero_rows(), don't call mark_as_null_row() for semi-join 
  materialized tables, because 1) they may have been already freed, and 
  2)there is no real need to call mark_as_null_row() for them.
  

This bug is the result of an incomplete/inconsistent change introduced into
5.3 code when the cond_equal parameter were added to the function optimize_cond.
The change was made during a merge from 5.2 in October 2010.
The bug could affect only queries with HAVING.

An outer join query with a semi-join subquery could return a wrong result
if the optimizer chose to materialize the subquery.
It happened because when substituting for the best field into a ref item
used to build access keys not all COND_EQUAL objects that could be employed
at substitution were checked.

Also refined some code in the function check_join_cache_usage to make it
safer. 

common icp callback in the handler.cc.

It can also increment status counters, without making the engine
dependent on the exact THD layout (that is different in embedded).

This bug led to wrong values of the use_count fields in some SEL_ARG
trees that triggered complains on the server side when executing the
test case for LP bug 800184 if a debug build of the server was used.
  
This was the result of the incomplete fix for bug 800184.
To complete it the following corrections had to be made:
- the copy constructor for SEL_TREE must call the new function incr_refs_all()
  instead of the function incr_refs(), because references to next key parts
  from any SEL_ARG tree belonging to the list of the first key part has to be
  adjusted.
- the method and_sel_tree of the class SEL_IMERGE must use the copy constructor
  of the SEL_TREE class to make a copy of its second argument before it ANDs it
  with any SEL_TREE tree from the processed SEL_IMERGE object.  
   

The bug was fixed with the code back-ported from the patch for LP bug 800184
pushed into mariadb-5.3.