STYLE: Pefer = delete to explicitly trivial implementations

This check replaces undefined special member functions with
= delete;. The explicitly deleted function declarations enable more
opportunities in optimization, because the compiler might treat
explicitly delted functions as noops.

Additionally, the C++11 use of = delete more clearly expreses the
intent for the special member functions.

SRCDIR=/Users/johnsonhj/src/jsoncpp/ #My local SRC
BLDDIR=/Users/johnsonhj/src/jsoncpp/cmake-build-debug/ #My local BLD

cd /Users/johnsonhj/src/jsoncpp/cmake-build-debug/
run-clang-tidy.py -extra-arg=-D__clang__ -checks=-*,modernize-use-equals-delete  -header-filter=.* -fix

Author: hjmjohnson

Diff for: src/test_lib_json/jsontest.h

@@ -162,8 +162,8 @@ class Runner {
   static void printUsage(const char* appName);
 
 private: // prevents copy construction and assignment
-  Runner(const Runner& other);
-  Runner& operator=(const Runner& other);
+  Runner(const Runner& other) = delete;
+  Runner& operator=(const Runner& other) = delete;
 
 private:
   void listTests() const;