Outdated Updated Shiftlogic Automatic Transmissions 4.34

Added rev-match throttle during downshifts on the modern automatic transmissions, based on two factors:
1. Shift time
The faster the shift, the more noticeable the engine inertia, the higher the rev-match throttle
2. Engine RPM
The higher the engine RPM, the more the RPM changes during downshifts, the higher the rev-match throttle
The rev-match throttle can be set using "modernATRevThrottle" jbeam.

Classic AT
LeGran/Wendover:
Retuned 4AT(3T21) to further reduce rpm fluctuations
Reintroduced the slushy 4AT(4T21) because why not