Include Database-Migration Tool

[matthewtrask]

A few things Ive noticed to help make this a more modern and extensible site:

• Composer Autoloader
• Database Migration Tool (Phinx)

I think these tools, as well as moving towards PHP 7, will help drive more contributions.

[heiglandreas]

Thanks for raising @rocketpastsix.

But:

• Composer Autoloader is already used in the project (yes, it's a bit hidden away in the init_autoload.php-File that handles Zend-Framework integration also for usage without composer)
• php.ug was one of the first websites running on PHP7 ;) So there's no need to move to PHP 7 as it's already there ;) (There's also a blog-post about the upgrade - http://andreas.heigl.org/2015/09/13/moving-php-ug-to-php7/ )

Nonetheless the idea of integrating a Database Migration Tool is great! (just yesterday I was thinking about it). So whoever wants to tackle it: Go ahead!