#68 Implement random jump and shuffled order 2 months ago

Ticket created by ~mallniya on ~exec64/imv

Random jump is pretty simple and quite useful navigation command, widely used in other image/video viewers, so let's keep it up. Secondly, though shuf doing bare minimum to view arbitrary collection of images in a random order, having switchable shuffle order is better at least in a sense that one can switch it off mid-air if needed.