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.
{
    if (!EnsureWalletIsAvailable(request.fHelp))
        return NullUniValue;
    if (request.fHelp || request.params.size() > 1)
        throw runtime_error(
            "getrawchangeaddress\n"
            "\nReturns a new Bitcoin address, for receiving change.\n"
            "This is for use with raw transactions, NOT normal use.\n"
            "\nResult:\n"
            "\"address\"    (string) The address\n"
            "\nExamples:\n"
            + HelpExampleCli("getrawchangeaddress", "")
            + HelpExampleRpc("getrawchangeaddress", "")
       );
    LOCK2(cs_main, pwalletMain->cs_wallet);
    if (!pwalletMain->IsLocked())
        pwalletMain->TopUpKeyPool();
    CReserveKey reservekey(pwalletMain);
    CPubKey vchPubKey;
    if (!reservekey.GetReservedKey(vchPubKey))
        throw JSONRPCError(RPC_WALLET_KEYPOOL_RAN_OUT, "Error: Keypool ran out, please call keypoolrefill first");
    reservekey.KeepKey();
    CKeyID keyID = vchPubKey.GetID();
    return CBitcoinAddress(keyID).ToString();
}
UniValue setaccount(const JSONRPCRequest& request)