CreateByteFile takes a slice of bytes & writes its contents to disk at fullpath using an io.Writer if the file does not already exist.

CreateDirectory attempts to create a directory with given dirname if it does not already exist.

CreateEmptyFile wraps os.Create and creates and empty file with at fullpath if it does not exist.

DirExists returns true if the directory dir exists; otherwise returns false.

FileExists returns true if the file of name exists; otherwise returns false.

ReadTillNul takes a slice of bytes b and reads up until it encounters the first null terminator, returning the bytes read up until that point as a string.

WriteJSONConfig takes an empty interface cfg, which is meant to be a *config.Config struct or a *GameList and writes it as JSON to disk at fullpath, overwriting any existing file.