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.
"    \"account\" : \"account\",    (string) DEPRECATED. The associated account, or \"\" for the default account\n"
            "    \"scriptPubKey\" : \"key\",   (string) the script key\n"
            "    \"amount\" : x.xxx,         (numeric) the transaction amount in " + CURRENCY_UNIT + "\n"
            "    \"confirmations\" : n,      (numeric) The number of confirmations\n"
            "    \"redeemScript\" : n        (string) The redeemScript if scriptPubKey is P2SH\n"
            "    \"spendable\" : xxx,        (bool) Whether we have the private keys to spend this output\n"
            "    \"solvable\" : xxx          (bool) Whether we know how to spend this output, ignoring the lack of keys\n"
            "  }\n"
            "  ,...\n"
            "]\n"
            "\nExamples\n"
            + HelpExampleCli("listunspent", "")
            + HelpExampleCli("listunspent", "6 9999999 \"[\\\"1PGFqEzfmQch1gKD3ra4k18PNj3tTUUSqg\\\",\\\"1LtvqCaApEdUGFkpKMM4MstjcaL4dKg8SP\\\"]\"")
            + HelpExampleRpc("listunspent", "6, 9999999 \"[\\\"1PGFqEzfmQch1gKD3ra4k18PNj3tTUUSqg\\\",\\\"1LtvqCaApEdUGFkpKMM4MstjcaL4dKg8SP\\\"]\"")
        );
    RPCTypeCheck(request.params, boost::assign::list_of(UniValue::VNUM)(UniValue::VNUM)(UniValue::VARR));
    int nMinDepth = 1;
    if (request.params.size() > 0)
        nMinDepth = request.params[0].get_int();
    int nMaxDepth = 9999999;
    if (request.params.size() > 1)
        nMaxDepth = request.params[1].get_int();
    set<CBitcoinAddress> setAddress;
    if (request.params.size() > 2) {
        UniValue inputs = request.params[2].get_array();
        for (unsigned int idx = 0; idx < inputs.size(); idx++) {
            const UniValue& input = inputs[idx];
            CBitcoinAddress address(input.get_str());
            if (!address.IsValid())
                throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, string("Invalid Bitcoin address: ")+input.get_str());