MinecraftForge/FML — pull request #281 by SirSmuggler (2013-09-03 20:47:08+00:00)
Title: Added interface to control villager spawn.

This will allow you to register a spawn condition handler for each of
your villager types. The handler is used to determine if the villager
type should be in the pool of avalibe proffesions when a new villager is
spawned.