clang-tidy fixes again (#1155)

* [clang-tidy] remove redundant string initialization

Found with readability-redundant-string-init

Signed-off-by: Rosen Penev <rosenp@gmail.com>

* [clang-tidy] switch to raw strings

Easier to read.

Found with modernize-raw-string-literal

Signed-off-by: Rosen Penev <rosenp@gmail.com>

* [clang-tidy] fix performance issues

Found with performance*

Signed-off-by: Rosen Penev <rosenp@gmail.com>

* fix extra comma warnings

Found with clang's -Wextra-semi-stmt

Signed-off-by: Rosen Penev <rosenp@gmail.com>

* remove JSONCPP_OP_EXPLICIT

This codebase in C++11. No need for compatibility with C++98.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

* remove JSONCPP_NOEXCEPT

This codebase is C++11 now. No need for this macro.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
diff --git a/include/json/value.h b/include/json/value.h
index bea2a56..dffc51a 100644
--- a/include/json/value.h
+++ b/include/json/value.h
@@ -67,8 +67,8 @@
 class JSON_API Exception : public std::exception {
 public:
   Exception(String msg);
-  ~Exception() JSONCPP_NOEXCEPT override;
-  char const* what() const JSONCPP_NOEXCEPT override;
+  ~Exception() noexcept override;
+  char const* what() const noexcept override;
 
 protected:
   String msg_;
@@ -421,7 +421,7 @@
   bool empty() const;
 
   /// Return !isNull()
-  JSONCPP_OP_EXPLICIT operator bool() const;
+  explicit operator bool() const;
 
   /// Remove all object members and array elements.
   /// \pre type() is arrayValue, objectValue, or nullValue