Make dgcov work with git

For MariaDB there exists a wrapper for gcov, GNU's test coverage tool. The MariaDB wrapper is called dgcov. It's a bit outdated because it only works with the old source control system bazaar and the MariaDB code repositories have been moved to Github.

The task is to make dgcov work with Github.

Some relevant links.

• The dgcov wrapper is found here: http://bazaar.launchpad.net/~maria-captains/mariadb-tools/trunk/view/head:/dgcov.pl
• dgcov documentation: https://mariadb.com/kb/en/mariadb/code-coverage-with-dgcov/