Next/Prev cover buttons

[ohrenkino]

Looking at this bug report, there seems to be a longer history of that object:

Cover preview / cover info cropping in Tag info

In v3.23c, the cover preview box was adjusted to fix this bug. However, I've noticed that since then until the current version - v3.26 - when loading a cover that fills the entire cover preview box, the cover art will crop part of the cover info + checkbox. Hovering over the cover info field brings it (info field) into view again, but now it's the cover info that will crop part of the cover art (and leave a tiny slit of cover on the left side). Enabling/disabling "Correct aspect ratio" will r…