MDEV-6138 show sysvar's help in I_S tables

INFORMATION_SCHEMA.SYSTEM_VARIABLES
INFORMATION_SCHEMA.SYSTEM_VARIABLES.GLOBAL_VALUE_ORIGIN
GLOBAL_VALUE_ORIGIN=AUTO
portability fixes for sysvar_* tests
make sysvars_* tests to work on 32-bit too
cleanup: remove unnecessary hack from federated/CMakeLists.txt
fix TokuDB not to build ft-index library when disabled
cleanup: my_init_dynamic_array2 -> init_dynamic_array2
cleanup: remove dead code
cleanup: sort struct members by size
SHOW and FLUSH for I_S tables.

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
move userstat tables to a plugin
rename status_user.test -> userstat.test
MDEV-6108 update userstat feature from percona server

TOTAL_SSL_CONNECTIONS columns in CLIENT_STATISTICS and USER_STATISTICS
MDEV-34 delete storage/ndb and sql/*ndb* (and collateral changes)

remove:
* NDB from everywhere
* IM from mtr-v1
* packaging/rpm-oel and packaging/rpm-uln
* few unused spec files
* plug.in file
* .bzrignore
MDEV-5749 Please add a .pc file to MariaDB for easy use via pkg-config
fix a big test
fix unstable test results