While regtesting with [bitcoin-spock](https://github.com/msgilligan/bitcoin-spock) I noticed at some point the transaction creation via `sendtoaddress -> CreateTransaction()` fails, because the created transaction is larger than `MAX_STANDARD_TX_SIZE`.

During the process a lot of raw transactions are created, which have smallish outputs and when then using `sendtoaddress`, it appears to attempt to create a transaction that spends too many of those dust-ish outputs.

The transaction to create does not have many outputs, but it looks like it's caused by the coin selection, which selects too many inputs. Testing was done with a 0.9 branch, but on the first glimpse I believe this issue is as well be present in 0.10. If this is a known issue, and if there is already a guard against this behavior, I'd be happy about a hint.

Sorry in advance, I do not have a test script to reproduce this issue in an isolated manner. A potential fix would probably require to adjust the coin selection, so that it selects a combination of coins, which, in addition to the size of the rest of the transaction, is still smaller than the limit.

{
    CMutableTransaction tx;
    tx.vout.resize(nInput + 1);
    tx.vout[nInput].nValue = nValue;
    tx.nLockTime = nextLockTime++;        
    set.emplace_back(COutPoint(tx.GetHash(), nInput), tx.vout.at(nInput),  1,  -1,  true,  true,  true,  0,  false,  0);
}
static void add_coin(const CAmount& nValue, int nInput, SelectionResult& result)
{
    CMutableTransaction tx;
    tx.vout.resize(nInput + 1);
    tx.vout[nInput].nValue = nValue;
    tx.nLockTime = nextLockTime++;        
    COutput output(COutPoint(tx.GetHash(), nInput), tx.vout.at(nInput),  1,  -1,  true,  true,  true,  0,  false,  0);
    OutputGroup group;
    group.Insert(output,  0,  0,  true);
    result.AddInput(group);
}
static void add_coin(const CAmount& nValue, int nInput, CoinSet& set, CAmount fee = 0, CAmount long_term_fee = 0)