References now are represented by the pairs (ref, ref_target) where ref is Ref (former Reference) instance and ref_target is Scriptable to apply the reference for.
To return the pair from Reference creation function Context.scratchRefTarget is used to store the target part.
This change allowed to extend XMLName from Ref eliminating the need for XMLReference.
git-svn-id: svn://10.0.0.236/trunk@163174 18797224-902f-48f8-a5cc-f745e15eee43
66d3751db4