If you do have the version 0.9.6.5 or higher you have the hotkey system for sure. Just press ESC, choose "Controls" and set up the hotkeys for the skills. Then in the map you can quick-switch between skills by just pressing the numbers on the keyboard and use the curretn active skill by pressing the skill button. I forgot which on the skill button was. (>.<) Should be close to the attack adn defend buttons on the keyboard.