Redis: added Command::ping() and Client::isConnected()

Redis/include/Poco/Redis/Client.h

@@ -116,6 +116,9 @@ public:
 	void disconnect();
 		/// Disconnects from the Redis server.
 
+	bool isConnected() const;
+		/// Returns true iff the Client is connected to a Redis server.
+
 	template<typename T>
 	T execute(const Array& command)
 		/// Sends the Redis Command to the server. It gets the reply

Redis/include/Poco/Redis/Command.h

@@ -252,6 +252,9 @@ public:
 
 	static Command rpush(const std::string& list, const StringVec& value, bool create = true);
 		/// Creates and returns a RPUSH or RPUSHX (when create is false) command.
+
+	static Command ping();
+		/// Creates and returns a PING command.
 };