fix incorrect merge

Fixed MDEV-385: mysqltest running with continue-on-error crashes on a non-SQL command producing an error 

client/mysqltest.cc:
  Added missing DBUG_VOID_RETURN

Thanks to Ivoz for pointing this out.

- Let QUICK_RANGE_SELECT::init_ror_merged_scan() call  quick->reset() only 
  after we've set the column read bitmaps. 

- Better error messages

This fixes that one again can run the test systems with many threads without having to increase fs.aio-max-nr.


mysql-test/include/mtr_check.sql:
  Ignore the INNODB_USE_NATIVE_AIO variable (may change during execution)
mysql-test/mysql-test-run.pl:
  Ignore warnings for failure to setup AIO
storage/innobase/os/os0file.c:
  Continue without AIO even if we can't allocate resources for AIO
storage/xtradb/os/os0file.c:
  Continue without AIO even if we can't allocate resources for AIO
storage/xtradb/srv/srv0start.c:
  Give an error message (instead of core dump) if AIO can't be initialized

The bug was the result of the incomplete fix for bug lp bug 1008293.

the new file is fully synced to disk and binlog index. This fixes a window
where a crash would leave next server restart unable to detect that a crash
occured, causing recovery to fail.

MDEV-359: Fix another case where switch-off semisync could cause a race that ended with server crash.

This one was when the code releases and reaquires the lock with pthread_cond_wait() - and semisync is switched off meanwhile.

The semisync code does a fast-but-unsafe check for enabled or not without lock,
followed by a slow-but-safe check under lock. However, if the slow check failed,
the code still referenced not valid data (in an assert() expression), causing a
crash.

Fixed by not running the incorrect assert when semisync is disabled.

This is XtraDB bug lp:1015109, introduced by innodb_split_buf_pool_mutex.patch

Comment the offending assertion, until the fixed XtraDB is available

MySQL introduced a class Deferred_log_events. This class keeps a pointer
last_added. The code was keeping this pointer around even after the memory
pointed to was freed, and later comparing the bogus pointer against other
allocated memory. This is illegal, and can randomly produce false equal
comparisons depending on whatever the malloc() subsystem decides to return.

- put back the result encoding in func_in.result (messed up by kdiff3)
- update .result for other tests (checked)

Virtual columns of ENUM and SET data types were not supported properly
in the original patch that introduced virtual columns into MariaDB 5.2.
The problem was that for any  virtual column the patch used the 
interval_id field of the definition of the column in the frm file as
a reference to the virtual column expression.
The fix stores the optional interval_id of the virtual column in the
extended header of the virtual column expression. 

Attempt to make it easier to upgrade mysql->mariadb on Ubuntu precise.
It looks like we were missing conflicts: and replaces: on packages
mysql-server-5.5 and mysql-client-5.5.

make sure that find_date_time_item() is called before agg_arg_charsets_for_comparison().
optimize Item_func_conv_charset to avoid conversion if no string result is needed

On localized Windows versions, Windows uses localized time zone names and contain non-ASCII characters.  non-ASCII characters appear broken when displayed by clients
The fix is to declare system_time_zone variable to have UTF8 encoding and to convert tzname to UTF8.