Moved checkpoints out of main, to prep for using them to help prevent DoS attacks

src/main.h

@@ -99,7 +99,6 @@ void IncrementExtraNonce(CBlock* pblock, CBlockIndex* pindexPrev, unsigned int&
 void FormatHashBuffers(CBlock* pblock, char* pmidstate, char* pdata, char* phash1);
 bool CheckWork(CBlock* pblock, CWallet& wallet, CReserveKey& reservekey);
 bool CheckProofOfWork(uint256 hash, unsigned int nBits);
-int GetTotalBlocksEstimate();
 int GetNumBlocksOfPeers();
 bool IsInitialBlockDownload();
 std::string GetWarnings(std::string strFor);