* config/allocator/new_allocator_base.h (__allocator_base): Add
	workaround for Doxygen bug #6945.
	* include/std/memory: Improve docs. Define group for pointer safety.
	* include/std/scoped_allocator: Improve docs. Use "undocumented"
	conditional to suppress documentation for implementation details.

From-SVN: r270807