Allow uploading to a custom Arduino

[sijk]

This lets users work with custom boards without needing to modify the library, which is useful for boards that use a different bootloader baud rate or have different reset behaviour.

For example:

        public static void Upload(string hexFile, string serialPort)
        {
            var options = ArduinoSketchUploader.GetModelOptions(ArduinoModel.Mega1284);
            options.BaudRate = 57600;

            var uploader = new ArduinoSketchUploader();
            uploader.UploadSketch(options, File.ReadAllLines(hexFile), serialPort);
        }

[kalapee]

Good