Restructure the src directory

It is split into
- /libgnucash (for the non-gui bits)
- /gnucash (for the gui)
- /common (misc source files used by both)
- /bindings (currently only holds python bindings)

This is the first step in restructuring the code. It will need much
more fine tuning later on.

libgnucash/engine/gncmod-engine.c

@@ -0,0 +1,81 @@
+/*********************************************************************
+ * gnc-mod-engine.c
+ * module definition/initialization for the Engine module
+ *
+ * Copyright (c) 2001 Linux Developers Group, 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 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, contact:                        *
+ *                                                                  *
+ * Free Software Foundation           Voice:  +1-617-542-5942       *
+ * 51 Franklin Street, Fifth Floor    Fax:    +1-617-542-2652       *
+ * Boston, MA  02110-1301,  USA       gnu@gnu.org                   *
+ *                                                                  *
+\********************************************************************/
+
+
+#include "config.h"
+#include <gmodule.h>
+#include <libguile.h>
+
+#include "gnc-engine.h"
+#include "gnc-module-api.h"
+
+GNC_MODULE_API_DECL(libgncmod_engine)
+
+/* version of the gnc module system interface we require */
+int libgncmod_engine_gnc_module_system_interface = 0;
+
+/* module versioning uses libtool semantics. */
+int libgncmod_engine_gnc_module_current  = 0;
+int libgncmod_engine_gnc_module_revision = 0;
+int libgncmod_engine_gnc_module_age      = 0;
+
+
+char *
+libgncmod_engine_gnc_module_path(void)
+{
+    return g_strdup("gnucash/engine");
+}
+
+char *
+libgncmod_engine_gnc_module_description(void)
+{
+    return g_strdup("The GnuCash accounting engine");
+}
+
+extern SCM scm_init_sw_engine_module(void);
+
+int
+libgncmod_engine_gnc_module_init(int refcount)
+{
+    if (refcount == 0)
+    {
+        /* initialize the engine on the first load */
+        gnc_engine_init(0, NULL);
+    }
+
+    scm_init_sw_engine_module();
+    scm_c_eval_string("(use-modules (sw_engine))");
+    scm_c_eval_string("(use-modules (gnucash engine))");
+    scm_c_eval_string("(use-modules (gnucash business-core))");
+
+    return TRUE;
+}
+
+int
+libgncmod_engine_gnc_module_end(int refcount)
+{
+    return TRUE;
+}