Include mysqlpump parallel backup tool

MySQL now includes a faster backup tool using parallel threads for backup processes in addition to the single threaded mysqldump utility. Now that this tool has transactional consistency, It would be a great benefit for it to be added to MariaDB's default client toolset.

Here are links referencing the transactional consistency issue being resolved:

http://www.tocker.ca/2015/08/03/mysql-5-7-8-mysqlpump-caveat.html
https://dev.mysql.com/doc/relnotes/mysql/5.7/en/news-5-7-11.html

The existing mysqlpump binary in the MySQL or Percona releases fails (trying to connect to MariaDB 10.1.23) with an error message that server version 5.7.8 or later is required. While most of the work is done by the client utility, I am sure this means that there are some server related hooks that must be in place or that the tool wants to ensure are available before executing. Inclusion of this new tool would definitely require reviewing the server hooks vs a simple code recompile before this could be released. It would be a huge improvement on current tools and ensure that MySQL/Percona users would be able to migrate to MariaDB with existing programs/processes largely unmodified though.