catchunks: increase retx limit and improve statistics

Increased the retx limit from 3 to 15 (default in Linux TCP).
Added statistics about skipped retransmission.
Cleaned up statistic output.

Change-Id: I66ce9ac9fa08f7492f84bec48b7464ddb1228ab1
refs: #4861 #4603
diff --git a/tools/chunks/catchunks/options.hpp b/tools/chunks/catchunks/options.hpp
index b078277..d3a564e 100644
--- a/tools/chunks/catchunks/options.hpp
+++ b/tools/chunks/catchunks/options.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2016-2018, Regents of the University of California,
+ * Copyright (c) 2016-2019, Regents of the University of California,
  *                          Colorado State University,
  *                          University Pierre & Marie Curie, Sorbonne University.
  *
@@ -36,7 +36,7 @@
 struct Options
 {
   time::milliseconds interestLifetime = ndn::DEFAULT_INTEREST_LIFETIME;
-  int maxRetriesOnTimeoutOrNack = 3;
+  int maxRetriesOnTimeoutOrNack = 15;
   bool mustBeFresh = false;
   bool isQuiet = false;
   bool isVerbose = false;