The reason that 'tovero' is outdated is because it means "tobiano and any other white pattern". One of those other white patterns is Frame, which can be lethal to a foal if a horse with frame is bred to another with frame. So by calling them 'tovero', people can forget that there is a chance that they are carrying a lethal gene, and we end up with a dead foal that could have been avoided.
As for what frame and splash are, they are two different white patterns. Frame causes white to move along the horses body horizontally, usually starting from the barrel. It generally leaves a frame of colour around the white, along the back etc, hence the name. This horse is a good example of frame and it's effects. However, frame is not thought to cause leg white, so this horse has some other white pattern too, I think splash and possible sabino.
Splash is another white pattern. It looks like the horse has run through paint, and it has splashed up on the horse. The markings tend to come from the bottom of the horse and move upwards, and have very clean edges. Face white tends to slip to one side, and cover the eyes. Leg white is often higher in the front than in the back.
Splash and frame are both thought to cause blue eyes, while tobiano and sabino are not thought to.