Build metacity as library so that plugins can link against it.

Renamed original main() to meta_main(); added wrapper main() into metacity.c.

src/core/main.c

@@ -386,7 +386,7 @@ void meta_select_display (gchar *display_name)
  * functions.
  */
 int
-main (int argc, char **argv)
+meta_main (int argc, char **argv)
 {
   struct sigaction act;
   sigset_t empty_mask;

src/core/metacity.c

@@ -0,0 +1,26 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
+
+/* 
+ * Copyright (C) 2008 Intel Corporation
+ * 
+ * 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 2 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+
+int
+main (int argc, char **argv)
+{
+  return meta_main (argc, argv);
+}