This is required to do anything on 1.8. Some docs on the system can be found at:
http://jabelarminecraft.blogspot.com/p/minecraft-forge-1721710-custom-entity-ai.html

I have started commenting out the old AI hooks in the porting process - so it will build without any AI initially, then we can get this side of things working correctly.

Dan appears to be working on this in: https://github.com/danbornside/FairyFactions/tree/entity.ai, so I will refrain from as much work on this system as possible (continuing a policy of commenting things out where possible instead of tweaking them).

This is one of the blockers for the port, and it doesn't look like he's updated in 2 weeks, so I am going to take a look at it after all.