Fix for Photoshop and WiFi issues on MacBook Airs

This MacBook Air Update update issues an important fix for both Adobe Photoshop and WiFi connections in MacBook Airs from mid 2013 onwards. The update fixes an intermittent loss in wireless connectivity and an issue with Adobe Photoshop which may cause occasional screen flickering. It also fixes an issue which may cause audio volume to fluctuate during video playback.