Beta ETK800 Hybrid 8.1.0

This update fixes a couple torque allocation issues which will be most noticeable on the sport and race configurations, as well as a couple AWD-related fixes. There will also be an update notice when the car spawns reminding everybody that a new core/common mod will be required for the next update to function. I'm moving the Lua code for the hybrid system to its own mod that this mod, the hybrid Citybus mod, and any future hybrid mods can all share without each mod needing to ship its own copy of the code.