Blank links ftw por Saschi

I added a configuration panel in which you can either add a list of domains you want the addon to run on or add a list of domains you want the addon not to run on.

Usecase 1: You need the functionality on only a few pages.
Usecase 2: You need the functionality on almost all pages but want to add some exceptions. In this case, also check the checkbox at the bottom of the configuration panel.