By Hilary Russ NEW YORK (Reuters) – Starbucks has hired a former McDonald’s executive to oversee technology as returning CEO Howard Schultz explores changes to the coffee chain’s drive-thru, mobile order-and-pay and other systems. Deb Hall Lefevre will become Starbuck’s chief technology officer on May 2, according to a spokesperson. She takes over for Hans Melotte, who served as interim CTO for five months. Changes are likely to include increasing personalization in the company’s mobile app for customers, as well as improvements to systems for employee training, scheduling and equipment mainte…