default and custom error pages response

+ refactoring in response.cpp (functions split)
+ added Client::clear()
+ added replace_all_substr() in utils.cpp

srcs/Client.hpp

@@ -10,10 +10,10 @@
 
 struct Request
 {
-	std::map<std::string, std::string>	headers;
 	http_method							method;
 	std::string							path;
 	std::string							version;
+	std::map<std::string, std::string>	headers;
 	std::string							body;
 };
 
@@ -38,6 +38,8 @@ class Client
 		std::string		&get_headers(const std::string &key);
 
 		void	parse_request();
+		void	clear();
+		void	clear_request();
 
 	private:
 		struct Request	_request;