Enable -fvisibility=hidden for src/misc/.

* configure.ac: Check for -fvisibility support.
* m4/ax_check_compile_flag.m4: New file.
* src/misc/common.hh: New file.
* src/misc/Makefile.am: Add common.hh, and adjust to use -fvisibility.
* src/misc/bareword.hh, src/misc/escape.hh, src/misc/formater.hh,
src/misc/intvcmp2.hh, src/misc/intvcomp.hh, src/misc/memusage.hh,
src/misc/minato.hh, src/misc/optionmap.hh, src/misc/random.hh,
src/misc/timer.hh, src/misc/version.hh, src/misc/bddop.hh: Include
common.hh and add SPOT_API tags.
* src/misc/acccompl.hh, src/misc/accconv.hh: Prepare for upcoming
move.
* src/sanity/style.test: Ignore SPOT_API tags.
* wrap/python/Makefile.am: Ignore SPOT_API.
* wrap/python/spot.i: Do not emit binding for bddalloc.hh.
* wrap/python/tests/minato.py: Do not use bdd_allocator.

src/misc/timer.hh

@@ -1,5 +1,5 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2009, 2011, 2012 Laboratoire de Recherche et
+// Copyright (C) 2009, 2011, 2012, 2013 Laboratoire de Recherche et
 // Développement de l'Epita (LRDE).
 // Copyright (C) 2004 Laboratoire d'Informatique de Paris 6 (LIP6),
 // département Systèmes Répartis Coopératifs (SRC), Université Pierre
@@ -23,6 +23,7 @@
 #ifndef SPOT_MISC_TIMER_HH
 # define SPOT_MISC_TIMER_HH
 
+# include "common.hh"
 # include "misc/_config.h"
 # include <cassert>
 # include <iosfwd>
@@ -200,7 +201,7 @@ namespace spot
     }
 
     /// Format information about all timers in a table.
-    std::ostream&
+    SPOT_API std::ostream&
     print(std::ostream& os) const;
 
     /// \brief Remove information about all timers.