Tractor Pulling Sled 1.4

Update adds 4 presets for my pulling mods
-Modified 4wd Truck
-Pro Stock Tractor
-Super Modified Tractor
-Unlimited Modified Tractor

*(also adds minor fixes)

Update Includes:
- Semi Wheels by default
- Weight to 35,000 lbs max
- Ability to change sled color
- Sled type has been switched from "prop" to "trailer"
- Tow Hitch Model Update
- Chain strengthened to not break after 1 pull
- Minor other fixes

-Added support for the Pintle Hitch Coupler found on the new T-Series Trucks as well as gooseneck hitch coupler option

-Added many new nodes for more realism

-Changed sled weight end stop so it no longer overhangs the end, which wasn't very realistic

Updated source file name to not conflict with original mod and removed a material file that shouldn't have been there