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

replace flag SHOW_VALUE_IN_HELP (that's not really an
independendent flag, as it should only be used for
NO_CMD_LINE sysvars) with a special getopt.id type.

their only purpose was to distinguish between
SHOW and SELECT and there are cleaner ways of doing  it.

* ignore the OPTIMIZER_SWITCH_ENGINE_CONDITION_PUSHDOWN bit
* issue a deprecation warning on 'engine_condition_pushdown=on'
* remove unused remains of the old pre-5.5 engine_condition_pushdown variable

MDEV-6606 Server crashes in String::append on selecting sql_mode inside anonymous block