Fix issue #1085: Draft search ignores discounts.

Note: the actual error isn't _NOT_ showing discounts (the transactions
  are posted with the discounts applied), but rather double counting
  (and a test-case where the discount is 50%).
(grafted from ead1395668002b870e78f817fd0bbf231867563f)

--HG--
extra : source : ead1395668002b870e78f817fd0bbf231867563f