Add framework for code style- and syntax-checking rules.

Almost all tests are initially disabled via the list in Makefile.cfg.
	* Makefile.am (EXTRA_DIST): Add .x-sc_avoid_if_before_free.
	Omit names of files that automake includes automatically.
	* .x-sc_avoid_if_before_free: New file.
	* build-aux/vc-list-files: Likewise.
	* build-aux/find-unnecessary-if-before-free: Likewise.
	* GNUmakefile, Makefile.cfg, Makefile.maint: New files.

Makefile.cfg

@@ -0,0 +1,62 @@
+# Customize Makefile.maint.                           -*- makefile -*-
+# Copyright (C) 2003-2007 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Use alpha.gnu.org for alpha and beta releases.
+# Use ftp.gnu.org for major releases.
+gnu_ftp_host-alpha = alpha.gnu.org
+gnu_ftp_host-beta = alpha.gnu.org
+gnu_ftp_host-major = ftp.gnu.org
+gnu_rel_host = $(gnu_ftp_host-$(RELEASE_TYPE))
+
+url_dir_list = \
+  ftp://$(gnu_rel_host)/gnu/coreutils
+
+# Tests not to run as part of "make distcheck".
+local-checks-to-skip =			\
+  po-check				\
+  makefile_path_separator_check		\
+  makefile-check			\
+  sc_no_have_config_h			\
+  sc_unmarked_diagnostics		\
+  sc_tight_scope			\
+  sc_trailing_blank			\
+  sc_GPL_version			\
+  sc_always_defined_macros		\
+  sc_cast_of_alloca_return_value	\
+  sc_cast_of_argument_to_free		\
+  sc_cast_of_x_alloc_return_value	\
+  sc_changelog				\
+  sc_dd_max_sym_length			\
+  sc_error_exit_success			\
+  sc_file_system			\
+  sc_obsolete_symbols			\
+  sc_prohibit_assert_without_use	\
+  sc_prohibit_atoi_atof			\
+  sc_prohibit_jm_in_m4			\
+  sc_prohibit_quote_without_use		\
+  sc_prohibit_quotearg_without_use	\
+  sc_prohibit_strcmp			\
+  sc_require_config_h			\
+  sc_root_tests				\
+  sc_space_tab				\
+  sc_sun_os_names			\
+  sc_system_h_headers			\
+  sc_the_the				\
+  sc_two_space_separator_in_usage	\
+  sc_useless_cpp_parens			\
+  patch-check				\
+  check-AUTHORS				\
+  changelog-check