If one calls `fundrawtransaction`, the change address will be retrieved from the keypool, though, this key/address will always be returned to the pool, leading to the problem that the next `getnewaddress()` call will restult in the same key/address.

Either we remove the auto-change-address (users would need to call `getrawchangeaddress` first [current best practice anyway]) or we add a call to keep/mark a specific key/address as change (after one have sent the funded raw transaction).

Reported by @NicolasDorier on IRC.
std::vector<uint256> vMerkleBranch; 
        READWRITE(tx);
        READWRITE(hashBlock);
        READWRITE(vMerkleBranch);
        READWRITE(nIndex);
    }
    void SetMerkleBranch(const CBlockIndex* pIndex, int posInBlock);
    /**
     * Return depth of transaction in blockchain:
     * <0  : conflicts with a transaction this deep in the blockchain
     *  0  : in memory pool, waiting to be included in a block
     * >=1 : this many blocks deep in the main chain
     */
    int GetDepthInMainChain(const CBlockIndex* &pindexRet) const;
    int GetDepthInMainChain() const { const CBlockIndex *pindexRet; return GetDepthInMainChain(pindexRet); }
    bool IsInMainChain() const { const CBlockIndex *pindexRet; return GetDepthInMainChain(pindexRet) > 0; }
    int GetBlocksToMaturity() const;
    
    bool AcceptToMemoryPool(const CAmount& nAbsurdFee, CValidationState& state);
    bool hashUnset() const { return (hashBlock.IsNull() || hashBlock == ABANDON_HASH); }
    bool isAbandoned() const { return (hashBlock == ABANDON_HASH); }
    void setAbandoned() { hashBlock = ABANDON_HASH; }
    const uint256& GetHash() const { return tx->GetHash(); }
    bool IsCoinBase() const { return tx->IsCoinBase(); }
};
/** 
 * A transaction with a bunch of additional info that only the owner cares about.
 * It includes any unrecorded transactions needed to link it back to the block chain.
 */
class CWalletTx : public CMerkleTx