Make several methods static.

Author: Nekto89

include/json/value.h

@@ -720,7 +720,7 @@ class JSON_API Path {
                     const InArgs& in,
                     InArgs::const_iterator& itInArg,
                     PathArgument::Kind kind);
-  void invalidPath(const JSONCPP_STRING& path, int location);
+  static void invalidPath(const JSONCPP_STRING& path, int location);
 
   Args args_;
 };

include/json/writer.h

@@ -249,7 +249,7 @@ class JSONCPP_DEPRECATED("Use StreamWriterBuilder instead") JSON_API
   void unindent();
   void writeCommentBeforeValue(const Value& root);
   void writeCommentAfterValueOnSameLine(const Value& root);
-  bool hasCommentForValue(const Value& value);
+  static bool hasCommentForValue(const Value& value);
   static JSONCPP_STRING normalizeEOL(const JSONCPP_STRING& text);
 
   typedef std::vector<JSONCPP_STRING> ChildValues;
@@ -323,7 +323,7 @@ class JSONCPP_DEPRECATED("Use StreamWriterBuilder instead") JSON_API
   void unindent();
   void writeCommentBeforeValue(const Value& root);
   void writeCommentAfterValueOnSameLine(const Value& root);
-  bool hasCommentForValue(const Value& value);
+  static bool hasCommentForValue(const Value& value);
   static JSONCPP_STRING normalizeEOL(const JSONCPP_STRING& text);
 
   typedef std::vector<JSONCPP_STRING> ChildValues;