Eris Action support

Latest CVS eris now correctly routes all in-game Atlas operations inherited from ‘action’ out to Entity’s Acted signal. This is a feature that has been broken for a long time, and enables client to start deploying single-shot animations in the world, for almost anything: talking, eating, combat. Many of the existing Cal3D models already contain a variety of such animations, so hopefully these can finally be made visible to players outside EntityForge.