Unique blacklist-classnames for php-code-coverage & phpunit

This is a follow-up to #226

The same "error" was caused by PHPUnit_Util_Blacklist, so i moved the classes to a static property, which can be used by phpunit (pull-request will be referenced).

SebastianBergmann\Comparator\Comparator is missing, as this is currently only part of the master-branch.