Inconsistency with `net.minecraft.entity.living.mob` and `net.minecraft.entity.mob`

[BlueStaggo]

In release 1.5, the package net.minecraft.entity.mob is what contains classes for mobs. However, in 1.6 this is changed to net.minecraft.entity.living.mob. This inconsistency makes it a bit tricky to work in a multi-version setup so it would be nice to see these packages kept at the same location.

[SpaceWalkerRS]

While this package change was deliberate, we should perhaps reconsider the entire package structure for entities. The reason for the split was that in 13w16a, the MobEntity class was split into two (LivingEntity and MobEntity), and generally in Feather, the entity package structure loosely follows the inheritance structure of entity classes.