Part Tire Installation Handler

# Installation Handler Overview
Name: Tire Installation Handler
Function: adds the ability to install parts as as tires on wheels installed on vehicle slots
From FVTM: yes

This Installation handler allows you to install a part as tire "into"
another part that is already installed as wheel on a WheelSlots.
You can enter here various settings of the tire for it to get only
installed into matching WheelSlots and Wheel parts.

Offset and other calculations are automatical from the values you specify
here and the values which are configured in the vehicle's WheelSlots.

Example config:

{
    "__comment": "Part JSON file.",
    "Installation":{
    	"Handler": "tire",
        "Removable": true,
        "OuterRadius": 8,
        "InnerRadius": 6,
        "Width": 4
    }
}

Here an overview of the available fields:

• Handler - the id of the wanted handler, it is tire
• Removable - (boolean) optional, if the part can be afterwards removed from the vehicle
• OuterRadius - outer radius of the tire (circle radius) in "pixel/texel" (16th of a block)
• InnerRadius - inner radius of the tire (prevents installation on too small or too large wheels)
• Width - width of the wheel