Switch from not desugaring *all* typedef that are declared within a class or...

Switch from not desugaring *all* typedef that are declared within a class or namespace inside std to not desugaring the typedef that are declared in std and are pointing to a class, enum or struct that is declared in std or __gnu_cxx (or a class or namespace nested within those namespaces).

This revises the behavior introduced in revision 46131.
This fixes <https://savannah.cern.ch/bugs/?100390>

Philippe.


git-svn-id: http://root.cern.ch/svn/root/trunk@48574 27541ba8-7e3a-0410-8455-c3a389f83636