Full-time 4WD for Hopper, Roamer, D/H-series 1.3

- Added a transfercase with adjustable rear torque bias
- Moved all configs from the extra configs mod to this one
- Adjusted values on viscous center differential
- Added a heavy duty viscous and 2 Torsen center differentials (one with locking, one without) as options
- Added a part that replaces rangebox gears, making the vehicle have no low range option, which is used in Speedster. Also removed Speedster's unique TC file as it was made redundant
- Adjusted and fixed all of the configs with some new parts and values
- Added a custom Superpig config
- Added a new stock Hopper config and replaced old Hopper 4WD with a new one (Hopper 365) based on Jeep Wrangler 392. May add an accurate component for replacing the center diff in the future, need to do more research on this one
- Fixed various bugs with the mod and adjusted some values to match official ones in vanilla transfer cases
- Redid the vehicle selector thumbnails to reflect changes, and have them up to date with new graphics