Combine conty build settings in a single file

Easier to modify them from a single file over patching files individually. This is a breaking change for anyone building conty from source as I have modified names of variables, uppercased them (so they are distinct from variables used in scripts) and changed types of some of them (e.g. converted packagelists to array & made booleans be truthful when they are set to any value, not some specific one).