table: reorganize PIT implementation

Merge pit-{face,in,out}-record.{cpp,hpp} into pit-entry.{cpp,hpp}
and merge pit-iterator.{cpp,hpp} into pit.{cpp,hpp}.

Rename get{In,Out}Record() to find{In,Out}Record(), following the
typical C++ pattern of using the verb "find" for functions that
return iterators.

No functional changes.

Change-Id: I6740dd6cfe92ca477938ab8dc2f6271fd8b6cc26
diff --git a/daemon/fw/strategy.cpp b/daemon/fw/strategy.cpp
index 712e200..47fd7d9 100644
--- a/daemon/fw/strategy.cpp
+++ b/daemon/fw/strategy.cpp
@@ -248,7 +248,7 @@
 {
   BOOST_ASSERT(pitEntry->getInterest().matchesData(data));
 
-  auto inRecord = pitEntry->getInRecord(egress);
+  auto inRecord = pitEntry->findInRecord(egress);
   if (inRecord != pitEntry->in_end()) {
     auto pitToken = inRecord->getInterest().getTag<lp::PitToken>();