Fix default value for innodb_compression_algorithm to 0 (uncompressed)
to avoid test failures.
Merge branch '10.1' of github.com:MariaDB/server into 10.1
Added default_role column to mysql_system_tables
Added extra error messages for default role.

Also fixed wording on one message.
Added default role implementation
Fixed comment.
Extended create_and_drop_role_invalid_user_table

Added extra check for default_role column.
Changed set_default_role_for test to clean up correctly
cleanup and updated test results