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/bloom.cpp

@@ -1,13 +1,15 @@
 // 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.
-#include <math.h>
-#include <stdlib.h>
 
 #include "bloom.h"
+
 #include "core.h"
 #include "script.h"
 
+#include <math.h>
+#include <stdlib.h>
+
 #define LN2SQUARED 0.4804530139182014246671025263266649717305529515945455
 #define LN2 0.6931471805599453094172321214581765680755001343602552