Improved content and layout of OFL button and tooltips


also getting rid of duplicated lines and error: 
sys1: PangoWarning: pango_layout_set_text: assertion `lenght == 0 || test !=
> Such a text + inline logo combination is less than ideal.

Then why not just write "Add SIL OFL" instead of just "Add SIL"? Or better yet, "Add Open Font License".

> Maybe "Fill in" instead of "Automatically add"? It's a helper that takes away some manual effort.

Fill seems weird. I don't think that any additional word is needed here.

> It's a helper that takes away some manual effort.

It seems self-evident that a button is a helper if you ask me. A button that does not do anything is a broken functionality. 
And it's not even done automatically, it's done at the push of the button.