Cleanup code using forward declarations.

Use misc methods of avoiding unnecesary header includes.
Replace int typedefs with int##_t from stdint.h.
Replace PRI64[xdu] with PRI[xdu]64 from inttypes.h.
Normalize QT_VERSION ifs where possible.
Resolve some indirect dependencies as direct ones.
Remove extern declarations from .cpp files.

src/ui_interface.h

@@ -2,13 +2,15 @@
 // Copyright (c) 2012 The Bitcoin developers
 // Distributed under the MIT/X11 software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
 #ifndef BITCOIN_UI_INTERFACE_H
 #define BITCOIN_UI_INTERFACE_H
 
+#include <stdint.h>
 #include <string>
-#include "util.h" // for int64
-#include <boost/signals2/signal.hpp>
+
 #include <boost/signals2/last_value.hpp>
+#include <boost/signals2/signal.hpp>
 
 class CBasicKeyStore;
 class CWallet;
@@ -71,7 +73,7 @@ public:
     boost::signals2::signal<bool (const std::string& message, const std::string& caption, unsigned int style), boost::signals2::last_value<bool> > ThreadSafeMessageBox;
 
     /** Ask the user whether they want to pay a fee or not. */
-    boost::signals2::signal<bool (int64 nFeeRequired), boost::signals2::last_value<bool> > ThreadSafeAskFee;
+    boost::signals2::signal<bool (int64_t nFeeRequired), boost::signals2::last_value<bool> > ThreadSafeAskFee;
 
     /** Handle a URL passed at the command line. */
     boost::signals2::signal<void (const std::string& strURI)> ThreadSafeHandleURI;