Remove dependency on Selectors and refactor codebase.

Change-Id: Ic3024b76ba0eea61f790c91c36090b4aa68702a3
Refs: #4522
diff --git a/src/common.hpp b/src/common.hpp
index bea3ddb..1a862d0 100644
--- a/src/common.hpp
+++ b/src/common.hpp
@@ -22,12 +22,11 @@
 
 #include "config.hpp"
 
+#include <ndn-cxx/data.hpp>
 #include <ndn-cxx/face.hpp>
 #include <ndn-cxx/interest.hpp>
-#include <ndn-cxx/name.hpp>
-#include <ndn-cxx/data.hpp>
-#include <ndn-cxx/selectors.hpp>
 #include <ndn-cxx/key-locator.hpp>
+#include <ndn-cxx/name.hpp>
 #include <ndn-cxx/security/v2/key-chain.hpp>
 #include <ndn-cxx/security/v2/validator.hpp>
 #include <ndn-cxx/security/validator-config.hpp>
@@ -55,11 +54,10 @@
 
 using ndn::Face;
 using ndn::Block;
+using ndn::operator ""_block;
 using ndn::Name;
 namespace name = ndn::name;
 using ndn::Interest;
-using ndn::Selectors;
-using ndn::Exclude;
 using ndn::Data;
 using ndn::KeyLocator;
 using ndn::Scheduler;
@@ -68,12 +66,6 @@
 using ndn::security::v2::ValidationError;
 using ndn::security::ValidatorConfig;
 
-using std::shared_ptr;
-using std::make_shared;
-using std::bind;
-using std::placeholders::_1;
-using std::placeholders::_2;
-
 using boost::noncopyable;
 
 typedef uint64_t ProcessId;