Add -Wextra-semi -Wundefined-func-template to the default CXXFLAGS

And fix the resulting compilation errors.

Change-Id: I16f679836a0cf2a3ff5dfcf6f6b67bfbfe4cdbd7
Refs: #4248
diff --git a/src/security/v1/sec-tpm-osx.cpp b/src/security/v1/sec-tpm-osx.cpp
index f43faa9..a54bf6e 100644
--- a/src/security/v1/sec-tpm-osx.cpp
+++ b/src/security/v1/sec-tpm-osx.cpp
@@ -1,5 +1,5 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
+/*
  * Copyright (c) 2013-2017 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
@@ -149,7 +149,7 @@
       CFRelease(m_typeRef);
       m_typeRef = nullptr;
     }
-  };
+  }
 
   bool
   operator==(std::nullptr_t)