Use gnulib-tool to create gnulib source files.

* Add gnulib files generated by gnulib-tool in build-aux, m4 and
    grub-core/gnulib directories
    * .bzignore: Add **/.deps and autogenerated gnulib files
    * configure.ac: Assign auxiliary directory to build-aux, add invocation
    of gnulib macros, add grub-core/gnulib/Makefile
    * Makefile.am: Add gnulib directory in SUBDIRS (removing unnecessary .),
    include m4 directory to aclocal.
    * Makefile.util.def: Remove direct compilation of gnulib source files
    and use the new grub-core/gnulib/libgnu.a.
    * build-aux/config.rpath: move config.rpath from top directory to
    build-aux
    * conf/Makefile.common: Remove the macro _GL_UNUSED already defined
    in gnulib headers
    * conf/Makefile.extra-dist: Add m4/gnulib-cache.m4
    * grub-core/Makefile.core.def: Remove unnecessary extra_dist
    * grub-core/lib/posix_wrap/localcharset.h (locale_charset): Update
    header.
    * grub-core/lib/posix_wrap/langinfo.h (nl_langinfo): Return static
    string.

m4/getdelim.m4

@@ -0,0 +1,90 @@
+# getdelim.m4 serial 6
+
+dnl Copyright (C) 2005-2007, 2009-2010 Free Software Foundation, Inc.
+dnl
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_PREREQ([2.59])
+
+AC_DEFUN([gl_FUNC_GETDELIM],
+[
+  AC_REQUIRE([gl_STDIO_H_DEFAULTS])
+
+  dnl Persuade glibc <stdio.h> to declare getdelim().
+  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+
+  AC_CHECK_DECLS_ONCE([getdelim])
+
+  AC_CHECK_FUNCS_ONCE([getdelim])
+  if test $ac_cv_func_getdelim = yes; then
+    dnl Found it in some library.  Verify that it works.
+    AC_CACHE_CHECK([for working getdelim function], [gl_cv_func_working_getdelim],
+    [echo fooNbarN | tr -d '\012' | tr N '\012' > conftest.data
+    AC_RUN_IFELSE([AC_LANG_SOURCE([[
+#    include <stdio.h>
+#    include <stdlib.h>
+#    include <string.h>
+    int main ()
+    {
+      FILE *in = fopen ("./conftest.data", "r");
+      if (!in)
+        return 1;
+      {
+        /* Test result for a NULL buffer and a zero size.
+           Based on a test program from Karl Heuer.  */
+        char *line = NULL;
+        size_t siz = 0;
+        int len = getdelim (&line, &siz, '\n', in);
+        if (!(len == 4 && line && strcmp (line, "foo\n") == 0))
+          return 1;
+      }
+      {
+        /* Test result for a NULL buffer and a non-zero size.
+           This crashes on FreeBSD 8.0.  */
+        char *line = NULL;
+        size_t siz = (size_t)(~0) / 4;
+        if (getdelim (&line, &siz, '\n', in) == -1)
+          return 1;
+      }
+      return 0;
+    }
+    ]])], [gl_cv_func_working_getdelim=yes] dnl The library version works.
+    , [gl_cv_func_working_getdelim=no] dnl The library version does NOT work.
+    , dnl We're cross compiling. Assume it works on glibc2 systems.
+      [AC_EGREP_CPP([Lucky GNU user],
+         [
+#include <features.h>
+#ifdef __GNU_LIBRARY__
+ #if (__GLIBC__ >= 2)
+  Lucky GNU user
+ #endif
+#endif
+         ],
+         [gl_cv_func_working_getdelim=yes],
+         [gl_cv_func_working_getdelim=no])]
+    )])
+  else
+    gl_cv_func_working_getdelim=no
+  fi
+
+  if test $ac_cv_have_decl_getdelim = no; then
+    HAVE_DECL_GETDELIM=0
+  fi
+
+  if test $gl_cv_func_working_getdelim = no; then
+    if test $ac_cv_func_getdelim = yes; then
+      REPLACE_GETDELIM=1
+    fi
+    AC_LIBOBJ([getdelim])
+    gl_PREREQ_GETDELIM
+  fi
+])
+
+# Prerequisites of lib/getdelim.c.
+AC_DEFUN([gl_PREREQ_GETDELIM],
+[
+  AC_CHECK_FUNCS([flockfile funlockfile])
+  AC_CHECK_DECLS([getc_unlocked])
+])