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.
{
    AssertLockHeld(cs_wallet); 
    setLockedCoins.erase(output);
}
void CWallet::UnlockAllCoins()
{
    AssertLockHeld(cs_wallet); 
    setLockedCoins.clear();
}
bool CWallet::IsLockedCoin(uint256 hash, unsigned int n) const
{
    AssertLockHeld(cs_wallet); 
    COutPoint outpt(hash, n);
    return (setLockedCoins.count(outpt) > 0);
}
void CWallet::ListLockedCoins(std::vector<COutPoint>& vOutpts)
{
    AssertLockHeld(cs_wallet); 
    for (std::set<COutPoint>::iterator it = setLockedCoins.begin();
         it != setLockedCoins.end(); it++) {
        COutPoint outpt = (*it);
        vOutpts.push_back(outpt);
    }
}
 
class CAffectedKeysVisitor : public boost::static_visitor<void> {