Optimizes small movements by entities by merging the movement
into the entities next larger movement, until enough movement
velocity has been hit.
This reduces collision detection and able to reduce movement
cpu cost by 5-7%.
The default option of 0.75 seems to provide all the gains without
any noticable behavior change to entity movement.
We have to exclude slimes due to weird jumping animation bugs.
When an itemstack runs out of durability, the amount is reduced to
0 which then marks the item as invalid. This causes the last unit
of durability to not apply enchantments as the enchantment level
check sees the item as a dud.
keep the clone of the item used to a non empty value so it represents
the item used.