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/rpcblockchain.cpp

@@ -3,8 +3,15 @@
 // Distributed under the MIT/X11 software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include "main.h"
+
+
 #include "bitcoinrpc.h"
+#include "main.h"
+#include "sync.h"
+
+#include <stdint.h>
+
+#include "json/json_spirit_value.h"
 
 using namespace json_spirit;
 using namespace std;
@@ -112,7 +119,7 @@ Value settxfee(const Array& params, bool fHelp)
             "<amount> is a real and is rounded to the nearest 0.00000001 btc per kb");
 
     // Amount
-    int64 nAmount = 0;
+    int64_t nAmount = 0;
     if (params[0].get_real() != 0.0)
         nAmount = AmountFromValue(params[0]);        // rejects 0.0 amounts