Clean up LedgerEntrySet and TransactionEngine:

* Reduce public interfaces
* Remove wrapper functions
* Remove freeze timed cutover code
* Return results directly instead of via ref parameters

src/ripple/app/misc/NetworkOPs.cpp

@@ -1045,7 +1045,6 @@ Transaction::pointer NetworkOPsImp::processTransactionCb (
         if (callback)
             callback (trans, r);
 
-
         if (r == tefFAILURE)
             throw Fault (IO_ERROR);