New models format

[tomangelo]

No, it wasn't. Models with such animations would be stored in parts models, that would be in any format that support such animations. Animations like these in text file were related to such animations like we got now in code. It was supposed to move some logic from code.
All this concept applies to interacting between models, that don't know about each other, because arm mesh might be connected to winged body, but it can be connected to tracked body too. At the end of this arm might be claws, but also it might be sniffer module. Relations between these models was supposed to be described in this file, but it doesn't interfere in these models themselves, so they can be animated like what you point at.
If there is possibility to import another files while exporting, then we only need to think out how to import lights, crashspheres/crashboxes and other object logic.