JAKARTA, Indonesia — Prabowo Subianto was inaugurated Sunday as the eighth president of the world’s most populous Muslim-majority nation, completing his journey from an ex-general accused of rights abuses during the dark days of Indonesia’s military dictatorship to the presidential palace. The former defense minister, who turned 73 on Thursday, was cheered through the streets by thousands of waving supporters after taking his oath on the Quran in front of lawmakers and foreign dignitaries.