- jQuery to 3.1.1
- jQuery UI to 1.12.1
- jQuery Migrate to 3.0.0

There are a few warnigs from migrate that have to be fixed. The toggles
in the Media Manager are also missing their proper icons.

This now pulls all data from official jQuery sources. Either their CDN
or their github account. Google tends to serve outdated or even broken
files :-(

Unfortunately there's no simple way to get the latest stable jQuery-UI
so for now the version has to be adjusted manually in the script.