moves A.super[B] into a separate tree called Aux.Super

this simplifies a lot of stuff and not only in scalareflect/core
a todo for attributes - something we have to design yet
introduces Aux.DualName.Sum and Aux.DualName.Product

The former services Term.This.qual, Mod.Private.within and Mod.Protected.within.
The latter is used in subclasses of Import.Selector.
Aux.Case.stats is now Seq[Stmt.Block]
pullrequest feedback
more feedback
more feedback
sketch of semantic APIs for dual names
ordering is important!
Ref.defn is gone, at least for the time being
Attribute.Ref => Attribute.Defn
fixes a typo
fixes compilation errors
Merge pull request #45 from xeno-by/master

moves A.super[B] into a separate tree called Aux.Super