cs: avoid Entry construction during query

Using C++14's transparent comparators, CS lookup logic can
compare stored Entry objects with the queried Name without
constructing an Entry object. This in turn eliminates the need
for a special "query entry", so EntryImpl class is deleted.

refs #4914

Change-Id: I5b05a1ab9ad696e79f7ebd6045be8de11cd58ee6
diff --git a/daemon/table/cs-policy-priority-fifo.cpp b/daemon/table/cs-policy-priority-fifo.cpp
index db13013..3c604ce 100644
--- a/daemon/table/cs-policy-priority-fifo.cpp
+++ b/daemon/table/cs-policy-priority-fifo.cpp
@@ -113,7 +113,7 @@
   if (i->isUnsolicited()) {
     entryInfo->queueType = QUEUE_UNSOLICITED;
   }
-  else if (i->isStale()) {
+  else if (!i->isFresh()) {
     entryInfo->queueType = QUEUE_STALE;
   }
   else {