Knex Gear creator

This is an OpenScad file that allows the user to create any Knex Gear (except maybe the spocket gear).

#### Use:
The use is made extremely simpel. The user needs only to insert the diameter of the knex gear. The amount of gear teeth is automatically calculated.

#### Options
The user then has some options to be turned on or off:
- Whether to add grappling arms.
- Whether to make the gear spin with or without resistance.
- Whether to add the notch at the top of the gear
- Whether to add the notch at the bottom of the gear (default disabled as it requires support to be enabled)
- Wheter to add small holes to the side (to mount the gear)

#### Pre builds
The default parameters are the parameters for a medium gear.
The JSON includes the parameters for the 1 to 1 gear, and the extra large gear.

#### Resolution
The top 3 parameters are used for the resolution of the part. By giving it a high resolution the quality of the part get's better, but loading times are slower. Therefore, start