Beta Hybrid Citybus 8.1.0

After studying planetary gearboxes and the transmission of a particular well-known real-life hybrid vehicle a bit more, I was able to analyze several issues that people were finding with the new eCVT transmission and I've now fixed them in this update. The transmission is now even smoother and does not produce "magic power" at high speeds.

The battery state management is better as well, meaning more of the "working range" of the battery can be used and the hybrid system will pull more power when needed even at low battery levels.

Finally, the hybrid system controls the engine RPM and load more intelligently so that the engine doesn't have to burn fuel to idle or coast. My initial testing with the citybus has yielded over a 50% improvement in fuel economy on every route I've tested versus the standard 4-speed bus!