Adjust author-width automatically

[franciscolourenco]

It doesn't make much sense to use abbreviated names and still take the same amount of space

[jonas]

With the above commit, you can set author-width = 10, and it will automatically abbreviate the author for you.

Regarding automatic resizing, with a proper heuristics it might make sense. I don't see much use for it though since I would expect every user to find a preference in terms of abbreviation/author-with size and just stick with that.

[franciscolourenco]

The way I would personally enjoy seeing it would be always displaying the full "standard" abbreviated version and taking only as much space as needed. Otherwise the option show-author=abbreviated gets a bit useless because; who wants to see the abbreviated version when they could be seeing the full version if the necessary space is being taken anyway?

The behavior one would expect from show-author=abbreviated would be for the space to get reduced automatically.
On the other hand, an even better behavior imo would be for it to take as much space required to display the largest of the abbreviated names and display the full version of other names if they are small enough to fit the space. This could be called show-author=dynamic for example.

Anyway, set author-width = 10 it already better so maybe this is low priority