orphaning mame-data-extras

Dear all, please be advised that I am orphaning mame-data-extras. This package has become too much of a burden to maintain with monthly mame releases one one hand and various files included in it lagging behind the mame releases on the other. Not to mention that it was in violation of code-vs-content guideline. I will be putting a dead.package in devel branch in about a week from now. Best regards, Julian