[Bug libstdc++/68792] New: Review doxygen output and don't install useless things

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68792

            Bug ID: 68792
           Summary: Review doxygen output and don't install useless things
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Keywords: documentation
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: redi at gcc dot gnu.org
          Reporter: redi at gcc dot gnu.org
  Target Milestone: ---

Currently with doxygen 1.8.9 the output for libstdc++ creates loads of useless
man-pages for implementation details that should not be in the public API docs:

std::tr2::__detail.3
std::_List_iterator.3

These should either be suppressed, or deleted after they are generated.

(with doxygen 1.8.10 we get a man page per header, which is even worse, but
that's a separate issue)

(See Bug 39868 for a different issue we had previously.)