Finalize autobridging implementation (RIPD-179):

Autobridging uses XRP as a natural bridge currency to allow IOU-to-IOU orders
to be satisfied not only from the direct IOU-to-IOU books but also over the
combined IOU-to-XRP and XRP-to-IOU books.

This commit addresses the following issues:

* RIPD-486: Refactoring the taker into a unit-testable architecture
* RIPD-659: Asset-aware offer crossing
* RIPD-491: Unit tests for IOU to XRP, XRP to IOU and IOU to IOU
* RIPD-441: Handle case when autobridging over same owner offers
* RIPD-665: Handle case when autobridging over own offers
* RIPD-273: Groom order books while crossing

src/ripple/app/ledger/LedgerEntrySet.cpp

@@ -1587,7 +1587,7 @@ TER LedgerEntrySet::rippleSend (
 
     if (QUALITY_ONE != transit_rate)
     {
-        saActual = multiply (saActual, STAmount::saFromRate (transit_rate),
+        saActual = multiply (saActual, amountFromRate (transit_rate),
             saActual.issue ());
     }