Integration with MCA API.

Make sure you have the release version of the API when it is officially
released with MCA v3.6.0. You shouldn't have to do anything except
update the API files.

Any mod implementing MCA's API should load before MCA. I've added dependencies = "before:mca" to CFGVillager.java. This does not mean MCA is required for CFGVillagers to run. 

I've also called the API to register whatever villager type you've registered with Forge's villager registry. Note that IDs between -1 and 7 are reserved for MCA. New villagers will be assigned a default texture included with MCA.