Lowering Slime Spawn Height

Before the update, it was relatively rare seeing slimes spawn outside of swamp biomes. Being that I spent most of my time above ground I didn't encounter slimes underground much unless I happened to mine out a space in a slime chunk, and even then it would have to be close to bedrock. Now that the new caves and depth limits are in, there is a lot more space and vertical area that slimes can spawn in. As a result of this (and the fact that they can spawn in a well lit area), there are slimes everywhere. It can be frustrating at times having to kill swarms of slimes to keep things nice and quiet. 

It would be great if the slime spawn height was lowered in conjunction with the current maximum depth, that way caves in the y=20 to y=-40 range won't be flooded with slime, as well as cleaning up underground builds.