Auto-step, like autojump but not so high

Basically, the issue with auto jump is that it pictures the player into the air every step which can be a bit unpleasant when done a lot (motion sickness? Not sure exactly). Manually jumping up to each the next step has the same problem.

Auto step would allow the player to move up one block exactly without jumping into the air, more like climbing steep stairs in real life. Useful when transversing unmodified terrain (i.e. no stairs).