Filled Monster Spawn Tweaks

Suggested name: Monster Spawn Tweaks

What I want:

More Monsters

Increase monsters in caves. This will make caves more dangerous and subsequently also reduce the amount of monsters on the surface because the spawnlimit is reached quicker in caves. It does this by increasing the packspawns with random monsters. So if a pack of 2 skeletons spawned 2 other monsters could spawn at the same time.

config.yml
#Maximum y value where packspawns are increased. Set to 0 to disable
Max Y: 55
# Multiplier. Normal packspawns are 1-4 monsters. A setting of 2 would increase it to 2-8.
# Note that this doesn't increase spawnlimits.
# If the spawnlimit is reached and no natural spawns occur this won't increase the limit.
Multiplier: 2

Monsters Spawn In Light

This works independent from "More Monsters". It spawns monsters even if there is sufficient light. Currently it will spawn monsters in locations where you have been previously. It's meant to make players not feel completely safe once they have lit up caves.

config.yml
#Feature enabled below 55 (caves). Set to 0 to disable
Monsters Spawn In Light Max Y: 55

Requirements:

Rules affecting all types of monsters (Both 1.7 and 1.8)
No commands or permissions needed.

When I like it by: When you have time to code this!

Thanks,
madtomic