Dipping their fingers in halal (permissible or lawful in traditional Islamic law) ink to prevent double voting, Indonesians will cast their ballots Wednesday in a bitterly contested presidential election, with the main rival to incumbent Joko Widodo already threatening to challenge the result over voter-fraud claims.The Muslim-majority nation's biggest-ever polls – with more than 190 million voters and 245,000 candidates vying for the presidency, parliament and local positions – is large