log start and end of Shutdown()

- could be helpful when debugging shutdown related problems

Rebased-by:   Warren Togami <wtogami@gmail.com>
Rebased-from: ced3c24816

src/init.cpp

@@ -89,6 +89,7 @@ static CCoinsViewDB *pcoinsdbview;
 
 void Shutdown()
 {
+    printf("Shutdown : In progress...\n");
     static CCriticalSection cs_Shutdown;
     TRY_LOCK(cs_Shutdown, lockShutdown);
     if (!lockShutdown) return;
@@ -114,6 +115,7 @@ void Shutdown()
     boost::filesystem::remove(GetPidFile());
     UnregisterWallet(pwalletMain);
     delete pwalletMain;
+    printf("Shutdown : done\n");
 }
 
 //