MySQL 5.6 implemented WL#344, which is about a MASTER_DELAY option to CHANGE
MASTER. But as part of this worklog, the format of the realy-log.info file was
changed. The new format is not understood by earlier versions, and nor by
MariaDB 10.0, so changing server to those versions would cause the slave to
abort with an error due to reading incorrect data out of relay-log.info.

Fix this by backporting from the WL#344 patch just the code that understands
the new relay-log.info format. We still write out the old format, and none of
the MASTER_DELAY feature is backported with this commit.

Stop spawning dummy threads on client library initialization

Let's revert the fix for Bug#24507.  To quote Monty from 2006:

"After 1/2 a year, when all glibc versions are updated, we can delete
this code."

Note: The upstream glibc bug was fixed in 2006.

Preserve CLIENT_REMEMBER_OPTIONS flag for compressed connections

Code cleanup: removed reference to CLIENT_REMEMBER_OPTIONS from server
code. This flag is ignored in MariaDB.

The INCIDENT_EVENT always caused slave error and abort, without checking
--slave-skip-errors.

Now, if error 1590, ER_SLAVE_INCIDENT is included in the --slave-skip-errors
list, incident events will be ignored.

This is a merge of this MySQL 5.6 patch:

revision-id: frazer@mysql.com-20110314170916-ypgin17otj3ucx95
committer: Frazer Clement <frazer@mysql.com>
timestamp: Mon 2011-03-14 17:09:16 +0000
message:
  Bug#11799671 NOT POSSIBLE TO SKIP INCIDENT ERRORS

Use single quotes for perl paths, in case of special symbols

Double-quoted string literals are subject to backslash and variable
substitution.

Fixed some compilation errors/warnings with ASan.

  Some variables weren't cleared properly so consequitive embedded server start/stop failed.
  Cleanups added. Also mysql_client_test.c extended to test that (taken from Mattias Johnson's patch)

When plugin=mysql_native_password (or mysql_old_password) take the password
from *either* password *or* authentication_string, whichever is set.
This makes no sense, but alas, that's what MySQL-5.6 does.

fix for ranges like "indexed_datetime OP time"
(test case is in the previous revision)

fix for ref like "indexed_time = datetime"

(prep for MDEV-6065)

The method JOIN_CACHE::init may fail (return 1) if some conditions on the
used join buffer is not satisfied. For example it fails if join_buffer_size
is greater than join_buffer_space_limit. The conditions should be checked
when running the EXPLAIN command for the query. That's why the method
JOIN_CACHE::init has to be called for EXPLAIN commands as well.

MDEV-4440 IF NOT EXISTS in multi-action ALTER does not work when the problem is created by a previous part of the ALTER.
        Loops added to the handle_if_exists_option() to check the
        CREATE/DROP lists for duplicates.

Part#1. 

table_cond_selectivity() should discount selectivity of table' 
conditions only when ity counts that selectivity to begin with. 

For non-ref-based access methods (ALL/range/index_merge/etc),
we start with sel=1.0 and hence do not need to discount any
selectivities.

- In table_cond_selectivity(), reset keyuse variable between the loops.

- Key_value_records_iterator::get_next() should pass pointer to the key 
  to handler->ha_index_next_same().  Because of a typo bug, pointer-to-pointer
  was passed instead in certain cases.

MDEV-6101 Hybrid functions do not add CURRENT_DATE when converting TIME to DATETIME