Move GetWarnings() into its own file.

src/warnings.h

@@ -0,0 +1,21 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2016 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_WARNINGS_H
+#define BITCOIN_WARNINGS_H
+
+#include <stdlib.h>
+#include <string>
+
+void SetMiscWarning(const std::string& strWarning);
+void SetfLargeWorkForkFound(bool flag);
+bool GetfLargeWorkForkFound();
+void SetfLargeWorkInvalidChainFound(bool flag);
+bool GetfLargeWorkInvalidChainFound();
+std::string GetWarnings(const std::string& strFor);
+
+static const bool DEFAULT_TESTSAFEMODE = false;
+
+#endif //  BITCOIN_WARNINGS_H