Fix galera_var_node_address.test

Fixed the bug mdev-12931.

This corrects the patch for mdev-10006.
The current code supports only those semi-join nests that are placed at
the join top level. So such nests cannot depend on other tables or nests.

Merge branch '5.5' into 10.0

Additions to 10.2.6 unstable-tests list

Add tokudb_bugs test to disabled.

MDEV-12624: encryption.innodb_encryption_tables fails in buildbot wit…

…h timeout

This regression was caused by MDEV-12467 encryption.create_or_replace
hangs during DROP TABLE, where if table->is_stopping() (i.e. when
tablespace is dropped) background key rotation thread calls
fil_crypt_complete_rotate_space to release space and stop rotation.
However, that function does not decrease number of rotating
threads if table->is_stopping() is true.

mysqld_safe_help - remove warning

/home/travis/build/MariaDB/server/extra/mysqld_safe_helper.c:62:21: warning: too many arguments in call to 'do_usage'
    do_usage(argv[0]);
    ~~~~~~~~        ^
1 warning generated.

Fix BuildBot Failure.

In some slave like p8-xenial-bintar-debug we are using C90 standard
which does not allow declaration and code to be mixed.

Make feedback plugin ON by default, for pre-release

Merge remote-tracking branch 'mysql/5.5' into 5.5