CelestialBodies.cs: Generate the bodies list by crawling the core's local body list.  This allows Kerbal Engineer to automatically support any future worlds Squad may add, and provide compatibility with world adding mods such as Kopernicus and Planet Factory.
CelestialBodies.cs: Don't add the root body in the system.  This is the sun without solar system modification mods, and the central gravitational influence on others.  This is beneficial because it won't add the central black hole in Star Systems, but still add the stars which orbit it.
Merge teknoman's celestial body fix.