* include/bits/basic_string.h: Fix iterator/index confusion in
	Doxygen comments.
	* include/bits/range_access.h: Fix Doxygen warnings.
	* include/bits/refwrap.h: Do not document implementation details.
	(ref, cref): Group docs with reference_wrapper.
	* include/std/fstream: Fix Doxygen markup.
	* libsupc++/initializer_list (begin, end): Group docs with
	initializer_list.

From-SVN: r270814