Add testcase.

Make log_slow_verbosity=explain actually print ANALYZE (that
is, EXPLAIN otuput with two extra columns).

Make ANALYZE work for
- ANALYZE SELECT ... INTO @var
- ANALYZE INSERT SELECT ...;
- ANALYZE SELECT .. INTO OUTFILE

Although the original code of mysql-5.7 was adjusted
to the current MariaDB code the main ideas of the optimization
were preserved.

Added API for atomic operations with explicit memory barrier. Only gcc
atomic builtins are currently supported. If they're unavailable, fall
back to atomic operations with implicit full memory barrier.

Add ANALYZE STMT handling into INSERT command.

remove:
* NDB from everywhere
* IM from mtr-v1
* packaging/rpm-oel and packaging/rpm-uln
* few unused spec files
* plug.in file
* .bzrignore

TOTAL_SSL_CONNECTIONS columns in CLIENT_STATISTICS and USER_STATISTICS

Extend existing plugins to support
* SHOW QUERY_RESPONSE_TIME
* FLUSH QUERY_RESPONSE_TIME
* SHOW LOCALE

move userstat tables to use the new API instead of
hand-coded syntax

INFORMATION_SCHEMA.SYSTEM_VARIABLES

1. @@boolean_var differs from SHOW VARIABLES
2. @@str_var ignored variable charset (which is wrong
   for path variables that use filesystem charset)
3. @@signed_int_var in the string context was printed
   as unsigned

it can never be set to NULL, so it should
not use MY_I_S_MAYBE_NULL flag either

old fix only generated a warning for the *first* row
in the output