removed workaround with SWIFT problems
Initial Version, moved the protocol definitions
moved old protocol part to model.swift
put node to public
removed UID (covered by GrapheElement)
moved protocol to model.swift
started to migrated SORelationship to Swift
cleanup old Objective C folders
test now Swift GraphContext
use now more Swift classes
removed import to  Foundation
corrected the store setup and the interface for property and relationship
added (empty) Property interface
removed public and corrected data type
removed public
more or less initial migrated version