Part category

Following is the list of possible part categories:

Category	Notes
`None`
`Production`
`Control`
`Structural`
`Aero`
`Utility`
`Science`
`Pods`
`FuelTank`
`Engine`
`Communication`
`Electrical`
`Ground`
`Thermal`
`Payload`
`Coupling`
`ColonyEssentials`
`Favorites`
`SubAssemblies`
`Amenities`
`Storage`