More Differential for original SCS Transmissions v1.0

This mod adds more differential for original SCS transmissions in ATS.
Differential ratio is a number which means how many times slower the axle rotates than the cardan shaft. The more differential ratio is - the slower your truck goes at the same RPM.
I made bigger differential ratios for more realistic driving and better handling of heavy cargoes. The last differential, 4.11, should be enough for carrying ~100 ton trailers.

The mod:
- does not replace anything, works as addon
- does not change gear names
- adds 3.25, 3.55, 3.73, 3.91 and 4.11 differentials for all vanilla transmissions
- has real differential ratio numbers
- works not only with Eaton 13 and 18 speeders, but with every transmission in the game including 10 speeders, Allison and 12 speeders
- has default prices and unlocks for all transmissions
- works with any version of the game
- works with any priority in mod manager