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/keystore.cpp

@@ -4,8 +4,13 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include "keystore.h"
+
+#include "crypter.h"
+#include "key.h"
 #include "script.h"
 
+#include <boost/foreach.hpp>
+
 bool CKeyStore::GetPubKey(const CKeyID &address, CPubKey &vchPubKeyOut) const
 {
     CKey key;