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/test/miner_tests.cpp

@@ -1,12 +1,14 @@
-#include <boost/test/unit_test.hpp>
 
-#include "init.h"
+
 #include "main.h"
+#include "miner.h"
 #include "uint256.h"
 #include "util.h"
-#include "miner.h"
 #include "wallet.h"
 
+#include <boost/test/unit_test.hpp>
+
+extern CWallet* pwalletMain;
 extern void SHA256Transform(void* pstate, void* pinput, const void* pinit);
 
 BOOST_AUTO_TEST_SUITE(miner_tests)