__traits proposal: derive hierachy and current-scope-type or something

[dennis luehring]

i've made an mistake

> module a;
> 
> class A{}
> 
   __traits( derivedClass, "A" ) => [ ]
> 
> -----


> module b;
> 
> class B:A{}

  __traits( derivedClass, "A" ) => [ "b.B" ]