Avoid duplication of typedefs in the list of selected TypedefsNameDecl
Reduce verbosity at level2
Fix ROOT-6517: autoload/parse of nested classes

allow the system to autoload/parse on nested classes.
The trick is simple: add as the autoload key the name of the "nesting"
class. This holds for classes and typedefs nested in classes.
Properly treat the NO_ROOTMAP argument with genreflex

thanks Philipp Schoppe for the joint debug session!