GUI-less build target bitcoind that links to wxBase and shouldn't need GTK,

split init and shutdown from ui.cpp into init.cpp,
support wxUSE_GUI=0
-- version 0.2.7

init.h

@@ -0,0 +1,7 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Distributed under the MIT/X11 software license, see the accompanying
+// file license.txt or http://www.opensource.org/licenses/mit-license.php.
+
+void Shutdown(void* parg);
+bool GetStartOnSystemStartup();
+void SetStartOnSystemStartup(bool fAutoStart);