Setup

In short: Moved everything to `uninstall.php`. Imho that file should be renamed to `setup.php`. Or if someone wants to *really, really*  use that crap, which is called "WordPress Coding Standards", then it should be `class-plugin-name-setup.php`.

I moved everything - including the callback hooked to the `wpmu_new_blog` hook - into that file. The file itself contains a class. All the logic that has previously been in place (like looping though blogs/blog IDs and calling single site actions/callbacks) have been moved as well. This makes the main file much more consistent.