No overflow, tab width changes to minimal size on hover

[rk-exxec]

I added a script, which widens tabs to a minimal width if you hover over them

[Timvde]

Hmm, actually, I'm thinking about removing the "infinite shrink" part, because it's already in https://github.com/Timvde/UserChrome-Tweaks/blob/master/tabs/prevent-tab-overflow.css. But I don't know if this tweak makes sense without it...