This is a combination of 3 commits.
- Coinselection prunes extraneous inputs from ApproximateBestSubset
A further pass over the available inputs has been added to ApproximateBestSubset after a candidate set has been found. It will prune any extraneous inputs in the selected subset, in order to decrease the number of input and the resulting change.
- Moved set reduction to the end of ApproximateBestSubset to reduce performance impact
- Added a test for the pruning of extraneous inputs after ApproximateBestSet
Github-Pull: #4906
Rebased-From: 5c03483e26ab414d22ef192691b2336c1bb3cb02 af9510e0374443b093d633a91c4f1f8bf5071292 fc0f52d78085b6ef97d6821fc7592326c2d9b495
* Introduce new constant MIN_CHANGE and use it instead of the
hardcoded "CENT"
* Add test case for MIN_CHANGE
* Introduce new constant for -mintxfee default:
DEFAULT_TRANSACTION_MINFEE = 1000
