[libxml++] Avoid infinite loop with Doxygen 1.8.6

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 91b437f9c27c29f8cc655fc60511724d1b32e08a
Author: Kjell Ahlstedt <kjell ahlstedt bredband net>
Date:   Tue May 20 08:57:25 2014 +0200

    Avoid infinite loop with Doxygen 1.8.6
    
    * configure.ac: Use the libstdc++.tag and libsigc++-2.0.tag files that were
    used when glibmm-2.4.tag was created.
    * docs/reference/libstdc++.tag.xml: Deleted file.

 configure.ac                     |    3 +-
 docs/reference/libstdc++.tag.xml |50080 --------------------------------------
 2 files changed, 2 insertions(+), 50081 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 10f866c..48706a0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -34,8 +34,9 @@ PKG_CHECK_MODULES([LIBXMLXX], [$LIBXMLXX_MODULES])
 AC_LANG([C++])
 AC_CHECK_HEADERS([string list map], [], [AC_MSG_ERROR([required headers not found])])
 
-
 MM_ARG_ENABLE_DOCUMENTATION
+MM_ARG_WITH_TAGFILE_DOC([libstdc++.tag], [mm-common-libstdc++])
+MM_ARG_WITH_TAGFILE_DOC([libsigc++-2.0.tag], [sigc++-2.0])
 MM_ARG_WITH_TAGFILE_DOC([glibmm-2.4.tag], [glibmm-2.4])
 
 MM_ARG_ENABLE_WARNINGS([LIBXMLXX_WXXFLAGS],